When Los Angeles Kings defenseman Drew Doughty vaulted Capitals center Nicklas Backstrom into the glass alongside the Capitals players’ bench early in the second period Tuesday night, 18,000 fans saw the Caps’ playoff hopes flash before their eyes.

After the game, Capitals coach Adam Oates said Backstrom did not return to the game for “precautionary” reasons, leading to speculation that his “upper body injury” may be to his left shoulder and not a concussion.

“We don’t play until Boston [on Saturday], a couple days,” Oates said. “Precautionary.”

Later in the third period, with 2:38 remaining in regulation, defenseman Jack Hillen and right wing Alex Ovechkin got into a nasty open-ice collision and Hillen appeared to lose consciousness on the ice.