(Patrick McDermott/GETTY IMAGES)

Lidge, a 35-year old reliever with 225 saves between the Houston Astros and Philadelphia Phillies, struggled since returning from the disabled list. Mattheus, a 2.25 ERA in 20 innings with the Nationals, had been on the disabled list since May 22 with plantar fasciitis in his left foot.

He made three rehab appearances, allowing three runs in three innings, for the Class A Potomac and Class AA Harrisburg.

The Nationals had said that Mattheus was close to returning and likely wanted him to make one more rehab appearance, but following Saturday’s 14-inning loss to the New York Yankees the team wanted to bring in another reliever.

“Brad wasn’t performing very well and was very disappointed,” General Manager Mike Rizzo said. “And Mattheus was ready to come off the rehab assignment and we thought this was the right time to make the move.”

Since returning from the disabled list on June 7 following sports hernia surgery, Lidge has been ineffective. He has allowed at least one run in three of the four appearances since. Against the Yankees on Friday, he allowed three runs on one hit and walked two.

In Saturday’s game, he allowed the winning runs to score, two runs on three hits in the 14th inning. Overall, Lidge has a team-worst 9.64 ERA and has allowed 10 runs in only 9 1/3 innings. Rizzo spoke with Lidge before Sunday’s game.

“He handled it like the professional that he is,” Rizzo said. “After his performance last night, he told me kind of knew there would be some kind of move in the bullpen. He said he was disappointed in the way that he pitched and sorry he couldn’t turn out better.”

The Nationals signed Lidge to a one-year, $1 million deal in the offseason to provide depth and experience to the bullpen. After closer Drew Storen got injured, the Nationals planned to lean on Henry Rodriguez, Tyler Clippard and Lidge in late-game situations. But Rodriguez struggled and got injured, and Lidge also fell to injury.

Rizzo said Lidge’s performance wasn’t as a result of lingering effects of his injury.

“I think he was healthy,” Rizzo said. “He said he was healthy and he threw like he was healthy, no pain, no after-effects after he was done rehabbing.