"He needs to work harder, he needs to work better," Vigneault said of Hart, according to NHL.com's Adam Kimelman. "I've had a good conversation with him ... about my expectations, about his practice habits and him stopping the puck."
The Flyers are facing the lowly Buffalo Sabres in back-to-back games on Monday and Wednesday night. Buffalo has lost 17 times in a row entering this mini series but the Flyers haven't been much better in that time, giving up a league-worst 66 goals in 15 games since March 1 and posting a 5-9-1 record.
Hart, 22, has posted a 20-8-9 record with a 4.04 goals-against average and a .869 save percentage in 22 games (20 starts) this season, but like his team has struggled in March. In 10 games (eight starts) this month, Hart has a .815 save percentage and a 2-6-0 record.
Brian Elliott, who started in Saturday's win over the Rangers, is expected to start both games against the Sabres. Alex Lyon is the team's third goalie on the taxi squad.