Your welcome. It may take a few days to a week, but things should start to return. He can do very light throwing (like 60%), but it is a good idea to give it a complete rest every couple of days. He also should make sure that as long as he pitches and plays a position, he save as many of his throws for pitching as possible. There is alot of unnecessary throwing that goes on at practice. Just think how many throws he cut out just by dropping balls in a bucket (which is what most of our IF'ers do anyway) instead of throwing them into a catcher. If a SS takes 50-75 groundballs during fielding work, that's 50-75 throws saved. Multiply that by the number of times in a week that they take fielding practice--and, well--you get the picture. As long as his arm is not sore or overly tired, things should return to normal in time. Just have him do everything he can to reduce the throwing load--even when he is throwing stronger again.
And, as an aside, I read your comment about the Reds pitchers. It is true you can sometimes just throw through it. However, when your throwing 92-93 and you lose 3-4 mph off your FB for a short time, it is alot different then when you are throwing 75-85 and lose that velocity.
PS...would love to hear the outcome...feel free to email me at pkosin2595@aol.com.