The injury delayed Stauffer's 2012 debut until Monday night, when San Diego opens a two-game series in Washington against Ross Detwiler and the Nationals.
"I'm definitely excited to get back out there," Stauffer said on Sunday. "It's been a long time in coming. But I feel ready to go."
The 29-year-old, the Padres' first-round Draft pick in 2003, went 9-12 with a 3.73 ERA in 31 outings last season. It was his first year in which he made more than 14 Major League starts.
"He pitched so well for us last year, and it looked throughout the winter that he was on a nice path to a good year," Padres manager Bud Black said. "It was a detour for Tim. He feels good, his pitch count is where it needs to be, and physically and mentally he feels where he needs to be."
In three Minor League rehabilitation starts at Class A Lake Elsinore and Triple-A Tucson, Stauffer posted a 1.72 ERA, struck out nine and issued no walks in 15 2/3 innings.
"Everything went well," Stauffer said. "I was able to get to each pitch count, and mechanically I felt good and was able to throw the pitches that I needed to work on."
Detwiler (3-2, 2.10 ERA) will start for the Nationals in a battle of two teams ranked among the bottom four in the National League in runs scored. Opponents have hit only .208 against Detwiler this season, with fellow southpaws going 2-for-29 (.069).
Detwiler took the loss on Wednesday against the Pirates, giving up three runs in six innings.
Padres: Some good news, finally
San Diego already has put 11 players on the disabled list this season, including outfielder Mark Kotsay, who missed the first 10 games with a strained right calf.
But Kotsay should avoid a repeat stint on the DL after leaving Saturday's game against the Phillies with lower back tightness. The veteran, who has started eight games in left field this season, told manager Bud Black that he was feeling better Sunday morning.
"He said last night that tomorrow [Sunday] will be big," Black said. "When I saw him today, he said that it felt good. We're going to do the best we can to stay away from him today."
Jesus Guzman started in left on Sunday, as Kotsay took the day off.
To make room for Stauffer on the 25-man roster, the Padres optioned left-handed reliever Josh Spence to Tucson after Sunday's loss to the Phillies. Spence had a 4.35 ERA in 11 appearances, and his demotion leaves Alex Hinshaw and Joe Thatcher as the remaining lefties in the San Diego bullpen.
Nationals: DL getting crowded
Like the Padres, the Nationals have been dealing with a string of injuries. That continued on Sunday, when the club placed starting catcher Wilson Ramos on the 15-day DL with a potentially season-ending knee injury.
Ramos tore the anterior cruciate ligament in his right knee while chasing a passed ball in the seventh inning of Saturday's game.
"He'll have to be operated on," manager Davey Johnson said on Sunday morning. "He'll be out most of the year. I don't know the severity of it, if it's just the ACL or if there are other complications, but we'll find out."
Ramos becomes the ninth Nationals player currently on the DL, joining Mike Morse, Jayson Werth and Drew Storen, among others. Sandy Leon was called up from Double-A Harrisburg to back up new starter Jesus Flores.
First baseman Adam LaRoche has helped Washington survive the injury bug, ranking sixth in the NL with a 1.012 OPS through Saturday. That success bucks his trend of slow starts, as LaRoche's career OPS is .721 for April, rising each month through August.
The Nationals, 12-4 at home, are beginning a seven-game homestand. The Padres, 3-9 on the road, are finishing up a five-game trip.
The Nationals took two of three games from the Padres in Washington this April, and this two-game set will be their last regular-season meeting.
Stauffer has a 1.66 ERA in four career starts against the Nationals, including 0.64 in two starts last season. His career road ERA is 4.73, compared with 3.06 at Petco Park.