Despite a less-than-ideal final pitching line, right-hander Taijuan Walker took another step toward the big leagues Thursday, showing progress in a few key areas en route to three great innings, one awful one and one so-so one. At the end of the night, he fanned eight and allowed five runs.

Walker dominated the first three innings and flashed a plus curveball, perhaps the best two I’ve ever seen him throw, to compliment his 88-91 mph cutter and four-seam fastball that teased 97 and sat 92-96.

The bad inning came in the fourth when Walker was up in the zone and lost some balance in his delivery. He hung a curveball that was hit out by former Mariners farmhand Mike Wilson in the third and then gave up several singles in the fourth that led to four more runs. He never lost his cool, however, and fought through some command issues in the fifth to get through the inning unscathed.

Long ball aside, the curveball was better for the most part; he’s had a tendency to telegraph the pitch some, something he didn’t do in this start, and he also flashed a couple of solid changeups to left-handed batters.

In the fifth, after issuing two walks and getting two outs, Walker worked Brandon Allen to a 2-2 count and struck him out on a hard changeup.

Note: I had originally labeled the 2-2 pitch to Allen a cutter, but Walker alerted me that it was a hard change.

Walker showed maturity, a better curveball and the same fastball life and use of his cutter that suggests he’s going to be very good, very soon. He had the bad inning — it happens, and he hadn’t had a hiccup in any of his first four starts in Triple-A — but there were still reasons to love what taking place at Cheney Stadium.

Walker is likely to make his big-league debut next month.

Robbie Erlin
Tucson left-hander Robbie Erlin made the start for the Padres Thursday. He sat 88-90 with his fastball, throwing from a high three-quarters arm slot but creating some arm side run that was effective versus right-handed batters. His curveball, clocked in the 72-75 mph range, showed well above average break, but he didn’t have good command of it in this start.

Erlin’s best pitch was his 80-84 mph changeup, which he threw for called strikes and induced a few swings and misses. His fastball command did him in versus Tacoma, who stacked nine right-handed batters against him, which can be counterproductive versus a changeup left-hander.

Erlin looked like a back-end starter Thursday, but if there’s a firmer fastball in that arm, he possesses the delivery and secondary stuff to be a solid No. 4 as early as 2014.

Notes
Stefen Romero is figuring out left field fairly well, showing better reads on fly balls and better routes to the ball. His arm is fringe-average, but he threw a perfect strike to the place twice Thursday on single to left … Abraham Almonte is a popular question for me on Twitter because he’s putting up solid numbers. He’s a below-average defender in center — perhaps passable, though — but runs well (low 4’s up the line including 3.55 on a drag bunt earlier this homestand), which qualifies as 65 or 70 grade speed. He’s a decent switch hitter, but has well below average power and profiles as a fourth or fifth outfielder … Rehabbing big leaguer Franklin Gutierrez appears 100 percent healthy and is swinging a solid bat for Tacoma. He may not be activated anytime real soon, but he’s closer to being ready at the plate than Michael Morse … Morse’s timing is still way off, suggesting the long layoff has reverted him back to spring training. He needs a few more days, based on what I saw Thursday … Stephen Pryor threw Wednesday and topped out at 90 mph. I’m told that was by design, however, as he’s working through some mild soreness in his right triceps and was just working on his command. He did show off the curveball and slider. He’s still a little ways away … Carter Capps is commanding his fastball — he went Thursday and looked solid — but his breaking ball, as expected, will need more time. He’ll be back in September.…

Seattle Mariners right-hander Taijuan Walker began the 2013 season back in Double-A Jackson where he spent all of 2012 because he needed to improve in several areas and the club correctly deemed the Southern League as the best place for him to take on such tasks. Tuesday, the 20-year-old showed how far he’s come in only four months and why he’s among the very top pitching prospects in all of baseball.

Walker, a sandwich-round selection in 2010 (No. 43 overall), used his stuff, poise beyond his years and a maturity level necessary for the circumstances to toss six shutout frames at the Fresno Grizzlies, allowing three singles and two walks, while striking out four. He threw 87 pitches, 56 for strikes, and for all 87 he appeared to be every bit the phenom he’s been cracked up to be since he burst onto the scene three summers ago as a raw 17-year-old.

The 6-foot-4, 210-pound Walker featured a four-seam fastball that sat 93-95 mph and touched 97, and came to the plate with ferocious downward plane, creating a very heavy ball, one extremely difficult to square up for hitters. He commanded the pitch down all night, missing only below the zone, not up, with some occasional arm side run and natural sink.

He worked his 90-93 mph cutter in often, helping set up a much-improved 71-74 mph curveball that froze batters all night. He sawed off several bats with the four-seamer and cutter and used the curveball with two strikes or to keep the Fresno lineup off balance.

He tossed a half-dozen or so below-average changeups in the mid-80s, but kept it down or away from left-handed batters and one in particular showed some fade, though each lacked sink. He maintained good arm speed on the pitch, but it’s still a ways from being more than a show-me offering.

Walker’s velocity didn’t dip much from the stretch — he sat 93-94 with runners on — and did not let some bad luck get to him. There were 4-6 borderline pitches on which he did not get the call from the home plate umpire, but he went back to work, rather than allowing it to get to him and affect his approach.

The four-seamer induced ground balls and the cutter forced poor contact that resulted in shallow fly ball outs and pop ups, and he did miss some bats with both pitches. His curveball is a full grade better today than in spring training or at any point a year ago, and he’s taken well to the cutter and seems to know how to use it.

Walker’s delivery was very consistent with one exception: He drops his arm slot slightly and opens up early on the curveball, which could be an issue against better hitters and it’s something he’ll need to fix for general consistency purposes, if nothing else, but big leaguers will see it and exploit it.

Walker’s velocity comes free and easy without much effort, which bodes well for his ability to hold that velocity deep — which he did through pitch 87 Tuesday and has done through the low-100s in the past — and if his high three-quarter arm slot can be maintained with the curveball, there’s no reason to believe he won’t max out and become a No. 1 starter. There may even be ace material here, though we’re likely a few years away from that kind of command from Walker.

I came into this start with one objective, which was to remain as objective as possible. Even doing so, it’s difficult to suggest Walker is on a path that will lead to anything but future stardom. That isn’t likely to occur in 2013, and while he’s likely to see the big-league mound in 2014, he may not settle in and succeed at a high level right away. His stuff, athleticism and his apparent acumen for progress may prove me wrong there, however.

He was very crude coming out of high school and in less than three years has gone from high-upside project to elite pitching prospect on the doorstep of the majors. He’s raised the ceiling on all of his grades since then — here’s my 2010 draft-day scouting report on Walker for subscribers — and now the sky is the limit.

After four innings, M’s scouting director Tom McNamara tapped me on the shoulder. I looked back and he gave me a look as if to ask, “so, what do you think so far?” My response?

“I’d be excited if I were you.”

Taijuan Walker is a phenom, and it may not be long before he’s toeing the rubber at Safeco looking to back up a Felix Hernandez gem with one of his own.…

A B C D E
1
NO. PLAYER POS AGE LEVEL
2
1 Kyle Lewis RF 23 A+
3
2 Noelvi Marte 3B 16 NA
4
3 Logan Gilbert RHP 21 NA
5
4 Julio Rodriguez RF 17 DSL
6
5 Evan White 1B 22 A+
7
6 Damon Casetta-Stubbs RHP 18 NA
8
8 Sam Carlson RHP 19 NA
9
7 Josh Stowers CF 21 SS-A
10
8 Braden Bishop CF 24 AA
11
10 Cal Raleigh C 21 NA
12
11 Juan Querecuto SS 17 DSL
13
12 Bryson Brigman SS 23 A+
14
13 Luis Liberato CF 22 A+
15
14 Daniel Vogelbach DH 25 AAA
16
15 Rob Whalen RHP 24 AAA
17
16 Art Warren RHP 25 AA
18
17 Seth Elledge RHR 22 A+
19
18 Matt Festa RHR 25 AA
20
19 Joe Rizzo 3B 20 A+
21
20 Wyatt Mills RHR 23 A+
22
21 Joe DeCarlo C 24 AA
23
22 Jansiel Rivera RF 19 SS-A
24
23 Anthony Jimenez OF 22 A+
25
24 Johendi Jiminian RHP 25 AA
26
25 Ronald Rosario RF 21 SS-A
27
26 Michael Plassmeyer LHP 21 SS-A
28
27 Joey Gerber RHR 21 SS-A
29
28 Eric Filia LF 26 SS-A
30
29 Max Povse RHP 24 AA
31
30 Holden Laws LHP 18 NA
32
31 Joe Rosa 2B 21 A
33
32 Ian Miller CF 26 AAA
34
33 Osiris Castillo SS 17 DSL
35
34 Brayan Perez LHP 17 DSL
36
35 Donnie Walton 2B 24 AA
37
36 Ryne Inman RHP 22 A
38
37 Luis Veloz OF 18 DSL
39
38 Jake Anchia C 21 SS-A
40
39 Joey O'Brien RHR 20 SS-R
41
40 Arturo Guerrero OF 17 DSL