The biggest loss was Karlsson, who played 10:32 in the first two periods, but was clearly laboring even when he did play. Karlsson has 16 points (two goals, 14 assists) in 19 Stanley Cup Playoff games.
Karlsson has been dealing with various lower-body injuries for much of the season and was on the bench for the majority of the third period of Game 4 on Friday, a 2-1 loss. He did not play in 27 of the Sharks' final 33 regular-season games but has not missed a game in the playoffs. He was averaging 25:32 time on ice per game before Game 5, second on the Sharks to defenseman Brent Burns (28:46).
Despite his reduced role in Game 4, he was in the lineup for Game 5 and before the game DeBoer said there were no issues.
"Hindsight is 20/20, you know," DeBoer said after the game. "We make those decisions based on the reports we get from the player and the medical [staff]. The report was that he felt he could play and get through the game. It's easy to sit here and say now, 'Yeah, sure you have regrets.'"
A turnover by Karlsson led to the first goal. Karlsson skated the puck to his own goal line and pivoted to pass to Dillon. The pass went off the boards and ended up on the stick of Oskar Sundqvist, who one-timed the puck past goalie Martin Jones, who was screened by Karlsson, at 5:50 of the first period.
"Just kind of an errant pass, just bounced off the wall and the guy was fortunate to tee one up like that," Dillon said.
The Sharks are 4-0 in elimination games, including three wins against the Vegas Golden Knights in the first round. Possibly without some key players, San Jose has to win consecutive games to make the Cup Final for the first time since 2016.
"We're still alive," Sharks forward Logan Couture said. "We've been in this spot before, going to Vegas down 3-2 in a very difficult building. St. Louis is similar, it's a tough building against a good team. A structured team. We scored one goal in the last two games, that's not going to cut it. We're not doing enough around their net or creating enough opportunities on second chances."