Frank Rodriguez had a rough weekend. He allowed 4 runs in 2 outings, surrendering 2 home runs in the process. One was to Diory Hernandez, he of the career .279/.331/.387 minor league triple slasher. More troubling than his home run-to-flyball regression is his velocity. His average fastball velocity this year is 90.3 mph, down from 91.1 mph last season and 92.7 mph in 2009. His early season velocity was in the 91-93 range, but in last night's game he was throwing in the high 80s, topping out at 89.9 mph. Friday night his top speed was 90.1 mph.

A decline in velocity is one indicator of injury. Taylor Buchholz's velocity was down several mph in his last few appearances before he was put on the disabled list. The same can be said for J.J. Putz in 2009. Rodriguez's strikeout rate is still strong (9.4 per 9 innings) but his swinging strike rate of 9.2% is a career low. It was 11.2% in 2010 and 12.3% in 2009. This is another sign that maybe something is amiss.

This could be blamed on small sample size fluctuation, wonky mechanics, the mysterious "dead-arm" condition or simply aging of a max effort pitcher. Or it could be some kind of injury. This is about as lazy an armchair diagnosis as possible but it's something to monitor over his next few appearances. Frankie with an 89 mph fastball could get old really fast.

And hat tip to me for not mentioning the vesting option until now.