I'd pick up John Lester too if Scott Olsen was my other option.

I'm carrying too many pitchers as it is while waiting for Hernandez and Verlander to realize they should throw the ball properly. I admit Lester was a knee-jerk reaction, but a Boston pitcher that's pitching well isn't a bad thing really. I have no worries the no-no will not be repeated. I'm looking more for wins than anything else at the moment. And ultimately I'll cut back on my roster by one or two pitchers down the road, most likely Lester will be one of them. No harm, no foul.
By all rights I have a good pitching staff. If I could erase the wasted innings in the first three weeks I'd be laughing, but as it is the ERA and WHIP are coming down. The K's are ok, at least on a per inning basis. Saves are sweet but wins are laughable. That'll change in time. I'll gain some points in pitching soon enough as my ERA falls while others climb. Same for WHIP.
I'd happily settle out with Marcum, Sabathia, Scherzer, Verlander and Fernandez providing the last two get it together.