There's a thoughtful post by Joe Janish on Mets Today on Thursday that raises the question of if Jerry Manuel is relying too heavily on Francisco Rodriguez this season. He's pitched on four straight days twice, and has pitched on three of the last four days with Manuel saying he would use him on Thursday night if needed.
Janish looks at K-Rod's history and finds that Mike Scioscia never used him on four straight days in 2008 and just once in 2007. On that occasion in 2007, Rodriguez got three days of rest before the stretch and four days of rest following it. Manuel has followed a similar protocol with K-Rod, but with a rough stretch of schedule before the All-Star Game his judiciousness will be tested.
The hard thing about these questions is that a definitive answer is very difficult to come by. If K-Rod comes down with a dead arm or loses velocity, we know that he was probably used too much. If he throws the whole season and the playoffs with no change in health or performance, we'll know that all was well.
One encouraging sign is that K-Rod has been using more fastballs and change-ups, something he did in 2008 as well. That's resulted in fewer strikeouts, but it is probably better for his arm than the copious amounts of breaking balls he was throwing before last year.
Something Janish doesn't mention, but which seems important to projecting K-Rod's future is how the J.J. Putz acquisition failed to work out. The Mets don't have a clear secondary option to use in a one or two run game if K-Rod has been used too often. Bobby Parnell needed Putz to have surgery for Manuel to trust him with high leverage innings, Pedro Feliciano is a specialist and Brian Stokes is used so rarely that he appears on milk cartons.
When push comes to shove, it would seem likely that Manuel would push the envelope more than Scioscia did with the Angels. Some of that is trust in other relievers, but some of that is job security as well. Scioscia has as much as anyone in baseball, while Manuel may need to get to October to keep his job. He's not going to risk that on something less than his best reliever.