CINCINNATI -- Reds first baseman Joey Votto is poised to take the next step toward his return from a knee injury.

Votto is slated to begin a two-game rehab assignment with Class A Dayton on Tuesday.

"I'm a little apprehensive, because I haven't played in such a long time," Votto said on Sunday. "Once I get going, I will feel fine."

Votto could rejoin the Reds for the Aug. 31-Sept. 2 three-game series at Houston.

"We're hoping he will be ready some time next weekend, if everything goes well," Reds manager Dusty Baker said.

Votto, 28, has been out of the Reds' lineup since July 16 and had surgery to repair a torn meniscus in his left knee on July 17. A setback from a sliding drill required a second minor procedure to remove cartilage on Aug. 10.

Last weekend, Votto resumed baseball activities and he advanced to hitting while the team was in Philadelphia earlier this week. He did pregame work with the team throughout this weekend.

"Pretty good," Votto said when asked how it was going. "I will progress today. I've got a long way to go with my swing."

It was decided this time that Votto would not do any sliding drills before resuming playing. Otherwise, there is nothing else he has to do to get himself ready for Tuesday.

"Just continue to progress I think," Votto said. "I'm sure that anything I'm uncomfortable with will stand out while I'm playing my rehab games, which is the best part about the rehab games."

Masset has setback, undergoes MRI on shoulder

CINCINNATI -- Reliever Nick Masset, who has not pitched all season because of a right shoulder injury, was back in the Reds' clubhouse on Sunday. And it was not for a good reason.

Masset's long rehab assignment hit another snag, and he underwent an MRI. He was waiting to hear the results from team medical director Dr. Tim Kremchek.

"I had a minor setback after Tuesday's outing down in [Triple-A] Louisville," Masset said. "There's a little bit of soreness in my shoulder. Right now, we're just working on getting to the next step. That's where I'm at right now."

In nine Minor League games at three levels, Masset has a 5.59 ERA, including six games at Louisville. On Tuesday, he gave up three runs, four hits and two walks without retiring a batter.

"I never felt anything while I was pitching," Masset said. "It's been tough, especially with the way the team has been playing all year. My biggest objective this year is to just get healthy and get back on the mound and ultimately get back on the team down the stretch. Unfortunately, I've had a couple of setbacks here and there. It's not helping my cause."

Stubbs gets breather for finale; Heisey starts

CINCINNATI -- As manager Dusty Baker indicated a day earlier, center fielder Drew Stubbs was given a rest from the starting lineup on Sunday. Chris Heisey started in Stubbs' place for the finale with the Cardinals.

Stubbs, who came in hitting only .227 this season with 14 home runs and 39 RBIs, struck out in seven consecutive at-bats on Friday and Saturday. He had four strikeouts Saturday until he snapped a 0-for-12 skid with an eighth-inning single.

"It sort of tears your heart out to see it," Baker said. "You know how much he wants it and how hard he's trying. It makes it worse when it's here at home. That's part of the deal."

Worth noting

• The Reds are the only team in the Majors to use a right-handed starter for every game this season. According to the Elias Sports Bureau, the Reds have had a left-hander start at least one game in every season since 1893, when the roster included ambidextrous pitcher Tony Mullane. Records weren't clear if Mullane actually started a game pitching left-handed, however.