According to the Palm Beach Post, general manager Mike Hill told players in the clubhouse after the game, but not all players were at their lockers, so some heard from other teammates.
The team announced the move after the game and also announced it had hired ESPN analyst Eduardo Perez to replace Mallee. Perez is the son of Hall of Famer Tony Perez, a special assistant for the Marlins.
Mallee, 42, was in his 10th season with the organization and was named hitting coach last July when Edwin Rodriguez took over as manager for Fredi Gonzalez. The team fired Jim Presley the same day it fired Gonzalez.
"I don't think it's right. I don't think it's just," outfielder Logan Morrison told the Palm Beach Post. "He had me prepared more than anybody.
"It's definitely not his fault. We let him down. Everybody has their finger on the panic button. It's hard to relax and play baseball."
Florida went into Wednesday's game hitting .255/.327/.382 with an OPS of .708, slightly above the league average. The Marlins are 10th in the National League with 239 runs scored.
The Marlins have lost seven straight, hitting .175 (11 for 63) with runners ins coring position during the streak, including 1 for 8 on Wednesday. Marlins president Larry Beinfest pointed to that stat as the biggest problem with the team and said he hoped the change would help.
Perez played for six teams, ending his playing career in Seattle in 2006. In his career, he hit .247/.326/.431.For more baseball news, rumors and analysis, follow @cbssportsmlb on Twitter or subscribe to the RSS feed.