The Reds activated McLain (calf) from the 10-day injured list Thursday.
McLain has been sidelined since early July with a left calf strain, but he's been cleared to return to action after going 5-for-17 with a 2:5 BB:K in five rehab games with Triple-A Louisville. The Reds also optioned Edwin Arroyo on Thursday, which could allow McLain to become the club's regular option at second base again. McLain has slashed just .190/.293/.328 with eight homers and 11 stolen bases this season.