Last night Trevor Rosenthal blew a save in the Cardinals eventual 4-3 victory over the Cubs. While that isn't very concerning, considering that Rosenthal had converted 10 straight saves prior to last night, what is concerning is that Trevor now has a 5.19 ERA while allowing 5.7 BB/9.
Could Rosenthal's struggles open the door for Jason Motte to return to the closer role?
Its possible, but probably not right away.
First, Motte has to make it back to the major leagues. He is still rehabbing at AAA Memphis and has yet to be promoted to the majors. While that could happen soon, there is always the possibility of a setback.
Second, Motte has to prove he's healthy and capable of getting major leaguers out. While he has yet to be scored upon, his velocity is still a bit down from his pre-surgery days. During his rehab his fastball has been sitting in the 91-95 mph range, whereas, prior to his injury, he was throwing around 98 mph. That may be good enough to get minor leaguers out, but is it good enough for the majors?
Finally, despite his struggles, Rosenthal has still only blown one save in 11 tries. That, by itself, is not enough to warrant a change.
However, what could precipitate a change are the walks. Last season, in 75.1 IP, Rosenthal only allowed 2.4 BB/9. This year, he has more than doubled that figure.
In addition, Rosenthal's velocity is down this year, from an average of 96.4 mph with a high of 101.4 in 2013, to an average of 95.9 with a high of just 98.7 this year. Could he be hiding an injury? Its possible, but until he comes forward, we just have to the weather and/or other factors.
Bottom line, with Motte's return eminent, Rosenthal had better get his act together or he could soon find himself in a setup role.