It is not yet clear just how significant an injury Montgomery is dealing with. Clearly, though, it’s a concern with only six weeks of the regular season remaining. He’ll be replaced in the rotation for the time being by Tyler Chatwood, with southpaw Randy Rosario being recalled to take the open roster spot.
Montgomery, 29, has been a godsend since moving into the rotation. In 13 starts, he has provided the club with 73 innings of 3.08 ERA pitching. While his 45:21 K/BB ratio in that stretch isn’t all that compelling, Montgomery does have a strong history of inducing groundballs. He has also consistently outperformed ERA estimators since reaching the majors, holding opponents to a .276 batting average over his career, though it’s certainly debatable whether that’s something we should expect to continue.
Regardless of one’s beliefs regarding Montgomery’s true talent levels, he has unquestionably represented a steadying force for a rotation that has dealt with a fair bit of uncertainty. With Yu Darvish slated to begin a rehab stint this weekend, there is at least the promise that he’ll be able to return before too long. But he’s still likely going to require a few outings and had struggled before hitting the DL. Meanwhile, turning to Chatwood really isn’t all that appealing an option. His control woes have continued since he was dropped from the starting five. In 5 2/3 innings over three relief appearances, Chatwood has allowed four earned runs and handed out five walks to go with three strikeouts.
Of course, the Cubs were not fully committed to utilizing Montgomery as a starter. They had just skipped his most recent outing, though that was said to have been done to keep him fresh. And while Montgomery has previously expressed consternation at being pushed to the pen, he seemed at peace with the possibility of spending time again as a reliever. Even if the plans may have called for an eventual return to the relief corps, though, that doesn’t mean that now was the preferred time. And it certainly does not draw the sting of any time lost due to injury. Montgomery, after all, would be quite useful to have in the bullpen while still constituting a key rotation depth piece. The Cubs will certainly hope he’s able to return to action in relatively short order.