Coming off a lengthy game yesterday and with Brad Lidge’s ERA at 9.64, the Nationals have decided to make a move.

The 35-year-old Lidge has been designated for assignment, while reliever Ryan Mattheus has been reinstated from the 15-day DL.

“The 14-inning game last night forced us to make a bullpen roster move,” general manager Mike Rizzo said. “Brad wasn’t performing very well. He was very disappointed, and Mattheus is ready to come off the rehab assignment. We thought this was the right time to make the move.”

Formerly one of the top closers in baseball, Lidge has battled health issues the last couple years. He was informed of the Nats’ decision to let him go during a meeting with Rizzo this morning.

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

Lidge was signed to a one-year, $1 million deal this offseason, and it looked like the Nats might have gotten a steal when the veteran righty tore it up in spring training. He allowed just one earned run in 10 innings, had 12 strikeouts to just one walk and held opposing hitters to a .132 batting average.

But the regular season was a different story. Lidge recorded two saves early in the season, but his performance quickly deteriorated. He missed 38 games after having hernia surgery in late April, but the results weren’t much better when Lidge was activated on June 7.

He finishes his Nationals’ tenure having allowed 10 runs, 12 hits and 11 walks in 9 1/3 innings. Hitters were batting .308 off him.

Mattheus was put on the DL back on May 22 with plantar fasciitis. He’s 2-1 with a 2.25 ERA this season.