A couple of injured Pirates infielders are on the mend and working their way back to the lineup.

Third baseman Josh Harrison will begin his rehab assignment with Triple-A Indianapolis on Tuesday. Harrison has been on the disabled list since July 6 with a thumb injury.

Meanwhile, shortstop Jordy Mercer is also expected to begin a rehab stint at Triple-A on Tuesday. Mercer suffered a knee injury on July 19 and was expected to miss six weeks. But his recover has gone a lot quicker than anticipated.

"We kind of took baby steps all the way up to the last couple days, when we really extended and pushed, and it’s responded really well," Mercer said Sunday, per the Pittsburgh Post-Gazette. There’s nothing else we or I need to do to confirm or tell myself I’m ready. We’ve checked all those boxes."