Locke was optioned upon being activated from the disabled list and his prospects are unclear.
"He'll be in the Indianapolis rotation, make starts, and we'll see where he can take them,'' a noncommittal manager Clint Hurdle said.
By contrast, Stewart, still on the DL recovering from right-knee surgery on March 19, has a pretty specific checklist.
"We've got a plan, and he's hitting the Indy portion, to get to [catching] a full game" Hurdle said. "We've got it all mapped out, and it's all predicated on how he feels the day after catching. We want to make sure he gets used the way we'll use him up here: Full game, maybe back-to-back full games, maybe some games he enters late.
"But as far as squatting, throwing, swinging, running the bases … he's met all the challenges."
The dynamics of Stewart's recovery are interesting. The longer he is absent, the greater chance for Tony Sanchez to have an impact and make it more challenging for the team to stick to its plan of optioning him when Stewart is ready. Sanchez is batting .333, and two of his four RBIs have been game-winners.