The Penguins lead the best-of-7 series 3-2. They will reach the Eastern Conference Final for the second straight year with a victory.
Daley played 11:09 in Pittsburgh's 4-2 loss in Game 5. He has one assist in 10 games during the Stanley Cup Playoffs.
Sullivan said he is undecided as to whether Chad Ruhwedel or Mark Streit will replace Daley in the lineup in Game 6.
Ruhwedel, 27, is a right-handed shot who never has played in the Stanley Cup Playoffs. Streit, 39, is a left-handed shot with 39 games of playoff experience but hasn't played since April 9, the Penguins' regular-season finale.
Of the six defensemen to play for the Penguins during the postseason, Justin Schultz is the only right-handed shot. Daley, Ron Hainsey, Ian Cole, Brian Dumoulin and Olli Maatta are left-handed shots.
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"I think it's nice to have the right-handed shot for sure," Sullivan said. "We've got a lot of left-handed shots. It just depends which way we want to go. We know that regardless of which guy we put in our lineup, they both can help us win games."
Ruhwedel said he's ready to go if the opportunity comes. He has not played since sustaining an upper-body April 6 against the New Jersey Devils.
"It's going to take a shift to get back to full game speed," Ruhwedel said. "But once that first shift's started then the rest will just take care of itself."
Defenseman Brian Dumoulin will play in Game 6 after skipping the morning skate because of a maintenance day.
