To mixed results, the Blues have made it through their last two games without Andy McDonald, but now with his concussion diagnosis official, they must find a longer-term solution to fill the void left by their leading forward in ice time.

McDonald was injured in Thursday's 3-2 loss to Dallas, and four days later, the club put the winger on injured reserve and acknowledged he will be out indefinitely with his second concussion as a Blue in 10 months.

"His symptoms were that the concussion continued to show," Blues general manager Doug Armstrong said. "We thought we'd get him on IR and just start to move forward. He's like (David) Perron in the sense that when he's healed and ready to get back on the ice, he'll come back with us."

The Blues will wrap up their four-game trip tonight in Los Angeles, where they'll keep looking for ways to be successful while offsetting the 19 minutes, 1 second of ice time they forfeit with McDonald's injury. After losing him Thursday, the team managed a 4-2 win over San Jose on Saturday, but fell 4-2 to Anaheim on Sunday.

The Blues moved T.J. Oshie into McDonald's spot at left wing on a line with center David Backes and Jamie Langenbrunner. The line scored one goal in the past two games, but it was an empty-netter by Backes against San Jose.

"They've had some tough assignments and they've held up their end of the bargain as far as making sure they're not giving up things," Blues coach Davis Payne said. "They had some chances when Andy was on that line. Now all of a sudden, we need someone to step up and give you some contribution there."