If you're scoring at home, it will be Niittymaki's eighth appearance (and seventh start) in the last nine games, including a flawless 43-minute relief appearance Saturday in a 4-3 comeback win in Boston.
Biron likely will play Saturday against the Islanders; Niittymaki will get the call in Sunday's more important matchup against the Rangers.
Niittymaki, 28, is 13-4-4, with a 2.48 goals-against average. He has been more consistent all season and has been especially effective in his last six games - a 5-1 record and a 2.07 goals-against average.
"To me, it's a maturing thing," Flyers goaltending coach Reggie Lemelin said. "A goalie matures right around 27 or 28. That's when you really hit your peak and I think Nitty's coming into that."
Biron, 31, is 15-11-5, with a 2.96 GAA. He has lost four straight and has a 3.98 goals-against average in his last five games.
"When you play and you're sharp, everything happens automatically," Lemelin said, "and there's some hesitation in his game and his decision-making. . . . I think when he gets his confidence back, everything will fall into place."
Stevens said the level of the goalies' play "will certainly play a part" in who starts most of the 30 remaining games.
"We're a little different than some teams in the fact we have two goalies we rely on a lot," Stevens said.
"Marty carried the load last year, and he's carried most of the load this year. But if you look at Nitty now, he's really come on and played well. My plan right now is to give them both time in the net."
One of the goalies figures to emerge and be the go-to guy in the playoffs. If the playoffs started tomorrow, that guy would be Niittymaki.
Niittymaki ($1.375 million salary) and Biron ($3.5 million) will be unrestricted free agents after the season. Both have said they would like to remain in Philadelphia. The Flyers could decide to try to sign both of them, but the more likely scenario is that they will pursue the goalie who carries them down the stretch.
"I've been here seven years and love the organization and love the city," said Niittymaki, who was including his three seasons with the AHL Phantoms. "My family loves being here. I have no reason to go anywhere. It's up to the Flyers and agents. I haven't really been thinking about it or talked to anybody about it. I don't really care about it right now."
The issue at hand is trying to win the Atlantic Division and secure a high seeding in the Eastern Conference.
"This is a team sport. I've been able to win a couple of games lately and they feel like I should play, so I'm going to play Thursday," Niittymaki said. "And we go from there."
Playing as frequently as he has in the last three-plus weeks, Niittymaki said, has made it easier to stay sharp. "But at the same time, you have to take care of yourself better and be ready for all the games," he said. "Mentally, it gets a little tougher, but I've played a lot of games before so it shouldn't be an issue."
Niittymaki was the Flyers' main goalie two years ago, when he had a 3.38 goals-against average for a Flyers team that had the league's worst record. This season, he has shaved nearly a goal from that average. Some of it has to do with having a better team around him, and some of it has to do with his maturity and the way he prepares in practices.
"You learn to know your game and learn to know your body a little bit," he said. "You know where you have problems and you're able to work on those things and not just go out there and work hard without having any goals."
Breakaways. Little-used defenseman Lasse Kukkonen cleared waivers and was sent to the Phantoms for a 14-day conditioning assignment. . . . Mike Richards and Scottie Upshall returned to practice; they have each missed the last three games because of the flu.
Contact staff writer Sam Carchidi at 215-854-5181 or firstname.lastname@example.org.