"I hope he doesn't put too much pressure on himself," Baker said on Wednesday. "This is an opportunity to get extended play. I'm making it as easier on him as I can by batting him [second] in front of Joey Votto. Now it's up to him. All I can do is give guys opportunity.
"It's how he handles playing every day -- that's where the strong stand out. I'm pulling for Heisey."
Heisey has been a role player since his first big league callup in 2010, which came as a result of Chris Dickerson going on the disabled list. Last season, he made 36 of his 80 starts in left field, while batting .265 in 120 games overall, with seven home runs and 31 RBIs.
"I'm here to do my job, and today's being in left field, starting," Heisey said. "That's what I'm going to do. I'm sad for Ryan. He's a good friend of mine and a teammate. Hopefully he gets back sooner than they expect."
Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, and follow him on Twitter @m_sheldon This story was not subject to the approval of Major League Baseball or its clubs.