This seems to come up more rarely than I realized, at least, when I'm not managing. Last appearance I can find by a Met pitcher playing another position is August 8, 1999, when Bobby Valentine had emptied his bench while getting blown out by the Dodgers. HIs bullpen was spent by the ninth, so rather than give Chuck McElroy a second inning after he had expended 32 pitches in the eighth, he sent McElroy out to left and brought in Matt Franco to pitch. Franco, in giving up one run on a hit and three walks, was the Mets' most successful pitcher on the day. McElroy, for his part, fielded a single and made a putout on a short fly to left center.