Feldman had taken X-rays of the knee, which showed no structural damage, but he still wanted a closer examination.
"The kid is a little panicked because the swelling is still there," Washington said of the 24-year old. "He wanted [team doctor Keith] Meister to look at it."
Washington said he wouldn't be surprised to hear either way, if the knee was damaged or undamaged. Still, the manager did seem optimistic.
"[We took the MRI] to help this kid relax and let him know nothing is wrong there, that's all it is," Washington said.
Feldman will rejoin the Rangers when they begin a four-game series in Oakland on Thursday.
One more game:
Brandon McCarthy will throw a simulated game on Thursday when the Rangers travel to Oakland due to his brief start on Tuesday. McCarthy, who was making his first start since Aug. 10 after dealing with a stress fracture in his shoulder blade, threw 35 pitches in two-thirds of an inning and faced just six hitters against the Tigers.
"After his game last night, he's gotta see some hitters," Washington said.
There were no health concerns for McCarthy, Washington said, they just want him to face another game-type situation.
"It's a shame you have to come back for the first time and face a team like this," Washington said of the Tigers. "But that's the way it fell."
Pitcher Armando Galarraga was promoted to the Majors for the first time after nine seasons in the Minors, the Rangers announced prior to Wednesday's game.
Galarraga, a native of Venezuela, had never advanced past Double-A before this season. He made four starts with Triple-A Oklahoma, including a seven-inning complete game shutout on Aug. 25. He was included on the Rangers 40-man roster so no subsequent moves were made.
Galarraga had pitched in 151 Minor League games before dressing for a regular-season Major League game for the first time against the Tigers.
Washington said a start wasn't guaranteed for Galarraga, who has appeared in just one game of relief while in the Rangers organization.
"We'll see how it works out," Washington said. "If any one of those guys were to get a start, and this is only my opinion, it would be [Luis] Mendoza. But right now both of them are just used for length."
Washington nearly had to suit up for Tuesday's game against the Tigers. Third baseman Ramon Vazquez, who came into the game in the ninth inning as a defensive replacement, injured his hand and Washington and the training staff came onto the field to take a look at it.
There were no other options at third base, as Jerry Hairston, who started the game at third, was lifted for pinch-hitter Hank Blalock in the eighth.
"I was telling [Vazquez] 'Let me have your spikes, you take my jacket,'" said Washington, who played 40 games at third base during his 10-year playing career.
Vazquez remained in the game and, joking aside, Washington said Frank Catalanotto would have been the emergency third baseman.
Left-hander Bill White, who was not with the team for their two games in Detroit, will rejoin the team in Oakland.
White returned to Alabama to be with his father, who is sick with cancer, but his father told him to return to the team.
"You're talking about thoroughbreds, not ponies. They finish what they start. You gotta beat their [rear end] to get them out of the ballgame." -- Washington, on Roy Halladay, C.C. Sabathia, and four others who lead the league in complete games. The Rangers are the only team in the American League without a complete game.
The Rangers travel to Oakland before returning back to the Midwest to face the Twins. Kevin Millwood (9-11, 5.31 ERA) will start against Chad Gaudin (10-11, 4.47) with the first pitch scheduled for 9:05 p.m. CT on Thursday at McAfee Coliseum.