The Philadelphia Phillies replaced hitting coach John Mallee with former manager Charlie Manuel on Tuesday.
The team currently ranks 24th in the majors in batting average (.245), 23rd in home runs (149) and 22nd in slugging percentage (.738).
The Phillies have lost five of their last six games and entered Tuesday in fourth place in the National League East, nine games behind the division-leading Atlanta Braves.
Manuel, 75, who currently works as senior adviser to the general manager, will assume the position for the remainder of the season.
Manuel compiled a 780-636 record in nine seasons as Philadelphia's skipper from 2005-13, capturing two pennants and the 2008 World Series championship.