Both players suffered injuries in Winnipeg's 4-2 win against the New Jersey Devils on Sunday and their statuses are in question for Tuesday's game against the New York Rangers at Madison Square Garden.
Miettinen, who was making his season debut Sunday after sitting out the first 17 games with an upper-body injury, suffered a lower-body injury when blocking a shot 17 seconds into his first shift Sunday.
"It was tough for him. He just got out there," Jets coach Claude Noel said. "It was the shortest shift in a comeback ever. I think he's OK. He's day-to-day and we'll see how he's doing [Monday]. It's tough because the guy has battled to get in the lineup and then down he goes again. "
Byfuglien was injured late in the third period. Noel said he "wrenched something" when he hit into the boards and diagnosed it as a lower-body injury.
Like Miettinen, Noel termed Byfuglien day-to-day and said he will be re-evaluated Monday.