Letang had missed the previous three games with a lower-body injury. Letang leads all NHL defensemen with 28 points in 27 games.
When pressed he added, "They're both very close and they're both practicing with the team and ... they're both very close. I guess there's a possibility that they both could play [Tuesday]."
Letang said after practice Tuesday morning, "I've been skating with the team, so obviously I'm feeling better. It's always good to get back as soon as possible. I hate sitting and watching games. I want to be back on the ice as quick as possible."
The Penguins are on an NHL season-high 12-game winning streak. Malkin and Letang each missed games because of injury earlier in the season too. The Penguins are 4-2-0 without Letang and 10-2-0 when Malkin does not play.
Malkin has five goals and 19 assists in 21 games this season; Letang has three goals and 25 assists in 27 games.
In other Penguins injury news, Bylsma finally acknowledged that forward Matt Cooke has been dealing with a nagging injury. Cooke has sat out morning skates in recent weeks but has not missed a game this season.
The third-line left wing, who has five goals and 10 assists in 33 games, was not on the ice for the morning skate Tuesday.
"He needed to get some practice in and did that [Monday]," Bylsma said. "But for Matt, it's best-case scenario for him to just be able to play and not be in the ice for two skates a day. Yes, he's playing with an injury or is hurt a little bit, but he's been on the ice and been 100 percent when he does play."