Both have seen time at designated hitter, where Reynolds started on Tuesday, as manager Buck Showalter continues to shuffle the O's lineup.
"Both guys have made some good plays and both guys have had some games where they weren't as good as they're capable of," Showalter said. "I think we're still kind of familiarizing ourselves a little bit."
Reynolds led all Major League third basemen with 26 errors last season despite playing only 114 games at the position before switching to first base late in the year.
Reynolds made an effort to improve defensively this offseason, shedding 20 pounds in hopes of increasing his mobility. But the results have not shown through 15 games at third in 2012, as Reynolds has posted an .850 fielding percentage, committing six errors in 40 chances. On Monday against Texas, Reynolds' ninth-inning throwing error led to five unearned runs in a 14-3 loss.
Betemit's play at the position has not been an improvement, however, as he has committed five errors in 32 chances for an .844 fielding percentage. Still, Betemit was optimistic about his defensive performance to this point.
"So far this year I'm doing good," he said. "I'm going to do what I do, just go out there and play."
Showalter said a dark horse at third is Ryan Flaherty, the only Orioles player aside from Betemit or Reynolds to start a game there this season. Flaherty, a Rule 5 Draft pick, is yet to commit an error in his two starts at third, although Showalter said a sample of five chances is hardly enough to make a definitive statement.
"I think the real question is Ryan," Showalter said. "We haven't really gotten a feel for him defensively yet, but I guarantee at some point this season something is going to happen, and we're going to get a real good look at him.
"I don't look at him as your prototype Rule 5 guy. We don't look at X number of days we have to keep him to keep him ours. I think if he would've come into our club independently, he would have made our club. I think everybody keeps talking about him as a utility guy that can play all over. I think in the future you're going to see him have a chance to be an everyday player."
Other possibilities at third include Bill Hall, who is playing third and hitting .265 for Triple-A Norfolk, and Miguel Tejada, who passed a physical Monday, signed a contract Tuesday and is taking part in extended spring training in Sarasota, Fla. Although the 37-year-old Tejada hit just .239 in 91 games with San Francisco before he was released last season, he posted a .985 fielding percentage in 44 games at third base.