Jon Lester is easily one of the best young pitchers in baseball. If I were to construct a rotation from scratch, he would be in it every time. That jibes with expert opinion, as evidenced by ESPN's recent Franchise Player Draft.
After battling back from cancer and re-establishing himself with the Red Sox, Lester has been a very effective hurler, posting an average ERA of 3.29 and an average WHIP of 1.24 from 2008 through 2010. In each of those seasons he was a horse, tossing more than 200 innings.
In fact, the only real knock on Lester is that he's routinely struggled in the month of April. Chalk it up to getting in shape or to the cold weather, but Lester's career numbers are arguably worse for April than for any other month. His Augusts have yielded a higher overall ERA—4.60 compared to April's 4.12—but April's WHIP of 1.40 and strikeout-to-walk ratio of 1.97 are his poorest efforts.
Still, Lester is hardly alone in needing some time to get comfortable with the season, and he's always improved his performance as the calendar turns. May, June and July have been his strongest months over the past three years.
Which is exactly why his 2011 campaign is beginning to raise some red flags.
I don't want to be too hard on Lester. It's certainly not time to panic, and his season totals are still respectable. But in a rather uncharacteristic way, he struggled mightily through the month of May, and he began June with a mediocre effort against the Yankees.
To be fair, pitching in the Bronx is never easy, and to escape with a "quality start" isn't a bad thing. On Tuesday night, the big lefty threw six innings, allowed three earned runs and walked one while striking out five. Nothing to get alarmed about in and of itself. But it marked the sixth straight start in which Lester has failed to exceed six innings of work and the fifth time in those six games in which he's allowed three runs or more.
Over the past month, Lester's ERA is 6.17. His WHIP is 1.71. He's thrown only 35 total innings in those six appearances. With the exception of a shutout start against Cleveland, one aided by Boston's seven-run first inning and the Tribe's subsequent surrender, Lester hasn't looked much like Jon Lester.
Granted, it's only six starts. But consider this: In three seasons from 2008 through 2010, Lester had a combined 17 post-April starts in which he allowed more than three earned runs. That's 17 out of 97 games.
This year? He already has four in six outings.
Taken on its own, this short stretch is easy enough to dismiss. But there's more to examine. Lester's walk rate (BB/9 IP), which was 2.8 in both 2008 and 2009, jumped to 3.6 last season. He compensated by giving up fewer hits; his H/9 dropped from 8.6 to 8.2 to a low of 7.2 over those three years.
In 2011, his walk rate is still elevated at 3.7, but his hit rate is up again at 8.5.
All of this information combines to paint a rather worrisome picture. Lester could obviously bounce back at any moment, turning such concerns into a fading memory. In fact, there's no reason to think that he'll finish the 2011 season with poor numbers.
But his current season ERA is 3.98, just over the league average of 3.96 for starters. His WHIP is up to 1.35 after last year's 1.20. Lester needs to find his command. Locating his pitches will limit the number of baserunners and permit him to go deeper into games. Unless he strings together a few good starts in June, this minor slump could become something more.