ST. LOUIS -- In need of fresh arms to shake up their ailing bullpen, the Nationals made a pair of roster moves prior to Tuesday night's game against the Cardinals.
Ryan Madson was placed on the disabled list and struggling lefty Sammy Solis was optioned to Triple-A Syracuse. Right-hander Trevor Gott and left-hander Tim Collins were promoted to take their place. Right-hander Erick Fedde was moved to the 60-day DL to clear room on the roster.
Koda Glover will serve as Washington's closer while Madson is on the disabled list, according to manager Dave Martinez, as the Nats are down to their fourth closing option with Sean Doolittle (foot) and Kelvin Herrera (shoulder) both joined on the DL by Madson, who was diagnosed with a lumbar nerve root irritation.
It's another change for a Nationals bullpen that has surrendered back-to-back late leads and deflating walk-off home runs. Washington has dropped five of its last seven games and its bullpen is 0-4 with a 9.00 ERA and three blown saves during those contests.
"Hopefully these guys will all come back here fairly soon," Martinez said. "They're getting better and we'll get them back, but right now we got guys that are qualified to do the job. They just got to go out there and make pitches. I've been talking to all of them about different roles they may have to do and I said just 'do your best, that's all you can do is do your best.'"
Madson, 37, was optimistic Monday that he would be able to avoid a stint on the DL, but after undergoing treatment and a workout, he was still sore when he arrived Tuesday. Martinez stayed away from Madson on Monday and the Nats did not want to be limited in the bullpen again, so while they are hopeful his stay on the DL will be short, they made the move.
Glover slots into the closer's role, despite having not appeared in a Major League game until this past Friday after battling a shoulder injury for most of the season.
"He's done it before, and he's been throwing the ball well, other than yesterday," Martinez said. "I got a lot of confidence in him."
However, Glover has appeared in three of the past four games and pitched in back-to-back games for the first time this season in either the Majors or Minors, which means Justin Miller would likely get the ninth Tuesday if a save situation were to arise.
Gott should help provide depth in the bullpen and Collins will fill in as the matchup lefty from the 'pen, a role in which Solis scuffled.

Once a major piece in their bullpen, the Nats optioned Solis after giving up the go-ahead homer in the eighth inning Monday, which raised his ERA to 5.24. His inability to get lefties out and to spot his fastball consistently has been his biggest hindrance and what the Nationals want him to work on at Syracuse.
"He's got to keep his head up," Martinez said. "At some point, he's going to be back and he's going to help us, but we got to get him out and figure out what's going on."
Worth noting
• Some good news for the Nationals' bullpen is that Doolittle threw off a mound Tuesday for the first time since landing on the DL with a stress reaction in his left foot. He told reporters he was still experiencing some discomfort, but has adjusted his mechanics enough to pitch through it for now.