Papelbon-Lester Hypothetical

A week or so ago, I was wondering about the Red Sox's 5th rotation spot and instead of just blogging about it, I sent my question to Ian Browne, the redsox.com beat writer. It appeared yesterday in his mailbag:

With Lester expected to replace Julian Tavarez in the starting rotation, I was wondering what would have happened if Papelbon had stayed in the rotation. Who would Lester have bumped? Certainly not Curt Schilling, Josh Beckett or Matsuzaka, and it's highly unlikely that Wakefield would have been moved. Would Papelbon have been moved back to the bullpen anyway? Or would Lester spend 2007 in the 'pen, getting spot starts if anyone had been injured?
-- Allan W., Mississauga, Ontario

That's definitely the best hypothetical I've had in a while. Honestly, I think Lester would have had to wait in the Minor Leagues until an inevitable injury occurred. Schilling, Beckett and Wakefield are all pitching at a very high level, and Matsuzaka is bound to figure it out soon. So it's hard to believe Lester would have bumped any of those guys had Papelbon wound up pitching out of the rotation.

However, I never really felt like Papelbon was going to be a starter for keeps. It always just seemed like he'd do it until he got medical clearance. Perhaps it would have worked out that Papelbon would have returned to the closer's role as soon as Lester returned. All I know is that in baseball, these problems always seem to work themselves out. Anyway, I felt like this hypothetical game was good mental exercise.