“The determining factor is just hope he could cover a little more ground in the outfield because of Mike’s knee,” Riggleman said. “Basically, it’s a defensive decision today.”

With Nix’s increased playing time and Morse’s struggles – he’s hitting .241/.275/.325 – it seems possible the left field spot could evolve into a platoon, with Morse facing left-handed starters and Nix facing right-handers. Riggleman, though, said it’s too soon to decide, given the current moving parts in the Nationals’ outfield.

“I’m not sure when Mike will be really ready,” Riggleman said. “I’m not sure when (Rick) Ankiel will be back. That’s a little far away to think too much about it.”

>>> Reliever Chad Gaudin was set to come off the disabled list today, but Riggleman said he is not close to returning. “He’s just got that general wear-and-tear soreness that doesn’t appear it’s going to be anything extremely significant,” Riggleman said. “But he needs to go pitch some rehab assignments before we see him.” He did not know when Gaudin may pitch in a minor league game.

The Nationals may not have room for Gaudin, who had a 6.48 ERA with 10 strikeouts and eight walks in 8 1/3 innings before being placed on the disabled list. Henry Rodriguez is out of minor league options and Brian Broderick is a Rule 5 pick, so taking either off the 25-man roster would jeopardize their place in the organization.