Miami Marlins manager Mike Redmond liked the idea of being able to challenge reviewable on-field calls though MLB's new replay pitch did raise a few questions in his mind.

"I definitely have some concerns probably like anyone does about the challenges but I'm sure those will all be answered in time" Redmond said before Friday night's homestand opener against the San Francisco Giants.

"I think everyone's in favor of getting the calls right. I think the biggest question is always going to be the pace of play."

Commissioner Bud Selig on Thursday said Major League Baseball planned to expand its video review process next season giving managers the ability to challenge reviewable on-field decisions.

MLB plans to give managers one challenge during the first six innings of a game then two from the seventh inning on. Challenged calls will be reviewed and decided by a league crew in New York City.

"These challenges are going to be big because it could be the outcome of a game" Redmond said. "What if you have more than one play in the first six innings go wrong? What if there's three? And you only have one challenge."

Redmond said he had yet to receive anything official about MLB's "challenge" plans but knew in spring training the league would use the 2013 season to study replay expansion.