"He's fine," Quenneville said of Hossa.
"I expect (Hossa) to play," Mayers said. "I'm going to prepare like I'm going to play and adjust if I'm not."
Hossa was a surprise scratch moments before Game 3 on Monday, suffering from what coach Joel Quenneville called an upper-body injury.
Hossa, who is tied for the team lead with 15 points in the playoffs, participated in warm-ups before Game 3 but was replaced by Ben Smith, who did not take part in the warm-ups.
The Bruins take a 2-1 series lead into Wednesday's Game 4.