"We have a loose schedule that will end up going day to day based on how he responds to it," Reds manager Bryan Price said. "We will get him to where he is back to back, but those will start with probably back-to-back seven-inning games. We'll get him to where he's catching back-to-back nine-inning games before we consider activating him. Until we get to that place, it's hard to say how long it will be.
"However, we anticipate him being ready before those 20 days are up."
Because of the warmer weather, all of Mesoraco's rehab games will likely be with Pensacola.
Mesoraco started the season on the 10-day disabled list, so he could continue to build his workload as he comes back from 2016 right hip and left shoulder surgeries. He also underwent left hip surgery in '15 and has been limited to 18 starts behind the plate the past two seasons.
In seven Cactus League games, Mesoraco batted .235 (4-for-17), but he also got a lot of at-bats in Minor League and extended spring games. There wasn't a total number of at-bats expected for Mesoraco before he is activated.
"I do know the length or the duration of his rehab combined with the at-bats he got in Spring Training and the at-bats he got in extended spring after we left," Price said. "I'm hoping he will equal or exceed what the other guys got, which would be in the 40-40-plus [range]."
• Reliever Austin Brice, who is on the 10-day DL because of inflammation in the right ulnar nerve of his elbow, will go to Pensacola on Friday to begin his rehab assignment.
"He threw a bullpen yesterday," Price said. "He's got some outings mapped out before he gets bumped up to Louisville. But we definitely see him in Triple-A when he's cleared to take on a regular workload."
Mark Sheldon has covered the Reds for MLB.com since 2006, and previously covered the Twins from 2001-05. Follow him on Twitter @m_sheldon and Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.