Claussen has been on the 15-day disabled list since mid-June because of rotator cuff tendinitis. He also suffered a back injury last month.
"Health-wise, I was fine," he said of Monday's game. "I'm ready to go."
The Reds have an open fifth starter's spot and need someone to pitch on Saturday against Atlanta. If he is in fact ready, the club would like to activate Claussen.
"We're going to talk about it sometime today or tomorrow and see," Reds manager Jerry Narron said. "We'll go from there."
The likely candidate to start if Claussen is not ready would be new arrival Kyle Lohse, who was a starter in Minnesota before a demotion to the bullpen.
"People are saying that. I'll see what happens," said Lohse, currently in a long relief role for Cincinnati.
Shack sent back:
With the club needing to make room for new acquisitions Tuesday, lefty reliever Brian Shackelford was the odd man out and was optioned to Louisville.
The Reds had lefty Bill Bray and added veteran southpaw Rheal Cormier in a trade with the Phillies on Monday.
There were no complaints over Shackelford's performance. In his third callup this season, he faced four lefty batters in four appearances and got them all out during tight situations.
Lefties batted only .125 (4-for-32) for the season against Shackelford, but right-handers were hitting .450 (9-for-20) during the previous promotions.
"The one thing I hope he does in Triple-A, I hope they use him for more than just one batter," Narron said. "I hope they use him against right-handed hitters."
Both Cormier and Bray have strong numbers against right-handed hitters this season.
Narron planned on using Bray mostly in the sixth or seventh innings, and Cormier in the seventh or eighth innings.
Injured reliever Matt Belisle (back) was feeling positive after throwing in a bullpen session on Tuesday.
"I feel better at this point than the first time around. I'm really pleased," said Belisle, who is on the DL for the second time this season. "It went great. I let it go for 17 minutes and did everything."
Belisle expected to throw in the bullpen once more and hoped to begin a rehabilitation assignment soon.
ESPN the Magazine recently gave 18 athletes, including Reds pitcher Bronson Arroyo, cameras to shoot a "day in their lives." The issue with Arroyo's photography hits newsstands on Wednesday.
Elizardo Ramirez (4-6, 4.22) will pitch for the Reds on Wednesday at 7:10 p.m. ET against the Dodgers and Brad Penny (10-5, 3.53).