ST. LOUIS -- The San Jose Sharks will be without defenseman Erik Karlsson and forward Tomas Hertl when they try to avoid elimination from the Stanley Cup Playoffs against the St. Louis Blues in Game 6 of the Western Conference Final at Enterprise Center on Tuesday (8 p.m. ET; NBCSN, CBC, TVAS).

Forward Joe Pavelski will be a game-time decision, coach Peter DeBoer said. Pavelski and forward Timo Meier did not take part in the morning skate, although Meier is expected to play.

Karlsson, Hertl and Pavelski were injured Sunday in a 5-0 loss in Game 5 that gave St. Louis a 3-2 lead in the best-of-7 series. Karlsson and Hertl did not make the trip to St. Louis.

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"We've relied on our depth all year," DeBoer said. "This isn't new to our group. We have depth and we have guys that can come in and get the job done."

Tim Heed is expected to play in Karlsson's place after skating as Brenden Dillon's partner during the morning skate. Heed has played in two playoff games this postseason, most recently on April 16 in the first-round series against the Vegas Golden Knights.

Forwards Dylan Gambrell and Marcus Sorensen are expected to dress. Micheal Haley, who played in Game 5, could be scratched.

"We know it is going to be a challenge, but we are excited for the opportunity," Sharks forward Logan Couture said. "There's a lot of guys in this locker room that are counted on to win, but you can't win a hockey game without a full team. Guys that are going to go into the lineup are going to be counted on to contribute, and guys that have been playing the whole way are also going to be counted on."

Gambrell has played one postseason game, going scoreless on April 26 in game 1 of the second round against the Colorado Avalanche. Haley has no points in 10 playoff games this year and played 7:42 in Game 5. Sorensen has been scratched for two of the past three games; he has five assists in 17 postseason games this year.

"I think if I get in, I'll be in for a reason," said Gambrell, who did not have a point in eight games with the Sharks during the regular season. "They want me to make an impact, so go out there and do it."

Heed is excited for the opportunity to replace Karlsson.

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"It doesn't matter who's in or out; kind of like the next guy in," said Heed, who had 13 points (two goals, 11 assists) and was plus-9 in 37 games during the regular season. "I played for Karlsson before, and [I'm] just excited to get out there."

The Sharks are 4-0 when facing elimination in the 2019 playoffs.

St. Louis coach Craig Berube said the uncertainty about the Sharks lineup will not affect his team.

"We're not going to change the way we have to take this game and how we have to play and the urgency we need and the desperation we need to win the game," he said. "It doesn't matter who's in the lineup for them. They're going to be a desperate, hungry team for sure.

"We can't change anything. We've got to be ready, no matter what. We need lots of urgency in this game. It's hard to close a team out."

Karlsson's last shift in Game 5 ended with 7:04 remaining in the second period. Hertl appeared to be shaken up by a hit from Blues forward Ivan Barbashev 10:40 into the first but remained in the game until he did not come out for the third. Pavelski was injured 1:21 into the third on a hit from Blues defenseman Alex Pietrangelo.

Karlsson is tied for second on the Sharks with 16 points (two goals, 14 assists). Hertl has 15 points (10 goals, five assists) in 19 games. Pavelski has nine points (four goals, five assists) in 13 games.