The hype-machine had been in full force for what turned out to be a disappointing 2014 season for Taijuan Walker. The former top prospect spent time on the disabled list with shoulder troubles and a prolonged stint at Triple-A while battling growing pains. All in all, Walker had a 2.61 ERA and a 3.68 FIP in the 38 innings he pitched in the big leagues.
Entering 2015, Walker would beat out left-hander Roenis Elias for the final spot in the Seattle Mariners rotation during Spring Training — a spot he has maintained since. Through 22 starts and 129 innings pitched entering Tuesday night’s games, he owns a 4.67 ERA and a 4.22 FIP with a 3.71 K/BB ratio.
While unspectacular, Walker has been one of the Mariners top pitchers this year — of course, this hasn’t been the same staff that was dominant last year. The right-hander is second on the club behind Felix Hernandez in innings pitched, strikeouts, and fWAR. His performance on the year is comparable to now former Mariner J.A. Happ with Walker posting better strikeout and walk rates and Happ posting better ground ball and home run rates.
Looking beyond ERA or FIP, we can see that Walker has lessened the free passes — 2.37 walks per nine compared to 3.08 per nine at Triple-A last year — and is generating more swings and misses on his pitches. His 10.5 percent swinging strike rate is only a percentage point lower than that of King Felix.
The biggest problem for the sophomore starter has been the long ball. His 21 home runs allowed are the most on the pitching staff. Some of that is likely due to the success opponents are having with hitting the fastball — Walker has allowed a .427 slugging percentage against and a .185 ISO against on the pitch this year.
If we were to go by xFIP and normalize his home run per fly ball rate, we’d have a 3.73 number, almost a full run better than his ERA. Just by watching Walker pitch this year, you can see that several of the home runs given up are a result of him not getting the ball down to where catcher Mike Zunino has called for it. It’s not a problem without a fix, but is something that needs to be improved on.
It’s important to remember that Walker is still only days away from his 23rd birthday. In his age-22 season with the Oakland Athletics, Mark Mulder posted a 5.44 ERA and a 5.27 FIP in 154 innings pitched. Jake Peavy posted a 4.11 ERA and a 4.99 FIP in 194 and 2/3 innings of work for his age-22 season. Really, this is meaningless trivia, but it’s the company Walker finds himself in with nine weeks to go in his age-22 season. Point being, it’s not unusual for talented arms to struggle some early in their careers.
With an estimated eight starts to go in 2015, Walker very easily could finish the season around the 1.5 to 1.7 fWAR mark. A near league average performance from the 22-year-old starter should be considered nothing less than a solid season and stepping stone for the future. Remember, he’s making the major league minimum while veteran starters are getting paid north of $10 million for similar performances.
Somewhat lost in the mix are the consequences of Walker’s overall workload, as pointed out by Ryan Divish of the Seattle Times. While manager Lloyd McClendon hasn’t mentioned a set innings limit or plans to start skipping Walker, the situation will be closely monitored. Including a couple of Arizona Fall League appearances, the right-hander threw 129 and 1/3 innings in 2015 after pitching 156 and 1/3 innings in 2013.
Of course, not all innings are made equal with the innings pitched against major league hitters taking a higher toll on pitchers than those thrown in the minors. Generally for younger pitchers you want to see the workload increase by around 30 innings per year to protect their arm. We famously saw this a few years ago when the Washington Nationals shut down Stephen Strasburg prior to the end of the season and playoffs.
Applying that 30-inning rule to Walker, we would expect to see his season conclude around the 160 inning mark, or in about five start’s time. If we add a little more weight to his 2013 innings total, we could probably push that estimation closer to the 175-inning mark. But then again, Seattle may choose to go the conservative route. We won’t know until that happens.
In a season mired with poor performance and disappointment, Walker’s progression has been a bright spot. The biggest challenge moving forward appears to be limiting the home runs with improved command.
A strong performance to finish the year, regardless of how many more innings he throws, should all but lock up a slot in the middle of the rotation for the right-hander next year. He isn’t the No. 2 starter we had hoped he’d become, yet, but he could blossom into a solid No. 3 as soon as 2016.