I’m very much looking forward to the Mike Mussina-Rich Harden pitching matchup tonight, but I suppose the big story is that Jason Giambi is returning to Oakland for the first time since his BALCO testimony was leaked.

Giambi may not even play, as he is struggling at the plate. Perhaps, as some suggest, he is failing because he stopped taking steroids in 2003. Giambi says he has been battling some minor injuries: a forearm cramp and a recent beaning.

Giambi may be right. Even when he was in Oakland, he was never the type of player who could hit with minor injuries. In Oakland, when he was nursing an injury, he would DH. Look at his career numbers as a 1B (mostly healthy) vs. as a DH (less healthy):

Just like in his recent struggles, his ability to walk didn’t suffer as a DH, but his batting average dropped a ton. The difference now is that his slugging percentage is down, too. That may just be a matter of sample size, though.

I doubt Giambi will ever be a great player again, because it’s unlikely he’ll ever be consistently healthy again. Mike’s recent study shows that players with similar stats to Giambi’s often ended up retiring soon thereafter. But I still think it’s possible he could put together another stretch of good fortune with his health, and have a John Jaha-like last hurrah before his body fails him at last.