The 32-year-old defenseman will be out a second straight game when the Penguins host the Chicago Blackhawks at PPG Paints Arena on Saturday (7 p.m. ET; NHLN, ATTSN-PT, NBCSCH, NHL.TV). He did not practice Friday after missing a 4-3 overtime win at the New York Islanders on Thursday.
Letang was injured in the third period of a 6-4 loss to the Boston Bruins on Monday.
"Obviously, we'd like to have him back as quickly as we can, but that's where he's at right now," coach Mike Sullivan said after practice. "We'll take each week as it comes, and I'll update as we go."
In his 14th NHL season, Letang has 12 points (four goals, eight assists) in 15 games. He had 10 points (four goals, six assists) in his first eight games before having two assists in his past seven.
Letang has 505 points (116 goals, 389 assists) in 762 NHL games, the most points by a defenseman in Penguins history. He won the Stanley Cup with Pittsburgh in 2009, 2016 and 2017.
Rookie defenseman John Marino has replaced Letang on the top pair with Brian Dumoulin.
The Penguins rearranged their power play without Letang and forward Patric Hornqvist, who is out longer term with a lower-body injury, on Friday. Letang normally quarterbacks the top unit with Hornqvist serving as the net-front presence.
Defenseman Juuso Riikola joined the top unit with forwards Sidney Crosby, Jake Guentzel, Alex Galchenyuk and Nick Bjugstad. The second unit had forwards Evgeni Malkin, Jared McCann and Dominik Kahun with defensemen Justin Schultz and Marcus Pettersson.
Pittsburgh is 0-for-22 with the man-advantage in its past 10 games and is 25th in the NHL this season on the power play at 13.3 percent.
"We've had some really good chances. It just hasn't gone in," Crosby said. "I think we're just trying to find a way to get one in and hopefully get some momentum. ... With different guys in different spots, maybe you react a little more instead of thinking.
"When you switch something up sometimes, you see if you can score a goal. When it comes to the power play, if you just get one in, you can build off of that."
