"Didn't feel too bad honestly," Solis said about the length of his outing. "I've done it once this season against the Marlins, and being a starter just kind of felt fine. I found my groove, and from there they just kept giving me the ball."
Since being promoted to the Majors when right-hander Matt Belisle landed on the disabled list on April 27, Solis has a 1.59 ERA in 13 appearances. He has become a versatile pitcher for Baker, who has used him as a long reliever, to match up against left-handers and at times late in the game.
"Solis was awesome, he did an awesome job," Baker said. "He saved our bullpen, he went three innings and allowed us to mix and match there at the end."
Belisle (calf) is nearing his return, but sending Solis back to the Minors will not be such an easy decision for Washington. The club has stretched out Belisle's Minor League rehab stint, perhaps because they have not decided what the corresponding move will be to make room in their bullpen. Baker danced around the question Saturday when asked about an update on Belisle's return.
"There's a lot of factors in these decisions," Baker said. "There's contracts, tenure, time involved, who has options and who doesn't. There's a fine line between baseball ops and baseball business. I'll let you know when we get to that point. We have a few decisions to make."
The Nationals would also like to sort out left-hander Felipe Rivero's struggles to get lefties out this season. He began Sunday with a slash line of .306/.395/.389 against left-handed batters, and that was before Jay Bruce hammered a three-run homer off Rivero in the seventh. The puzzling part is that Rivero has had success against right-handers, who were hitting .107/.167/.250 for an OPS of .417 before Sunday.
"We certainly need him because he has dynamite stuff," Baker said. "We just can't figure out why he's not getting these left-handers out and he's getting right-handers out, which is his primary job. We'll go back to the drawing table and [pitching coach] Mike Maddux will figure it out."
Jamal Collier covers the Nationals for MLB.com. Follow him on Twitter at @jamalcollier. This story was not subject to the approval of Major League Baseball or its clubs.