Coach Marc Trestman said Tuesday that London will have surgery to repair an injured meniscus in a knee suffered in a 24-12 win at Toronto on Sunday. He expects the lanky receiver to be out of action for four-to-six weeks.
Anderson suffered a concussion and will sit out a game Saturday at Saskatchewan.
The offence was already missing its leading receiver S.J. Green, who may be ready to return next week, and running back Brandon Whitaker, who is gone for the season with a knee injury. They are also missing kick returner Trent Guy with a concussion.
The good news for Trestman was that linebacker Marc-Olivier Brouillette will be able to play, although he'll be wearing a cast on a fractured wrist. And receiver Eric Deslauriers, who had sore ribs, is also ready.
The fifth-year coach is down to two healthy regular receivers, Jamel Richardson and Brian Bratton, and is using third-string running back Chris Jennings. But he isn't overly concerned.
"It's exciting and challenging," he said. ''It's part of football.
"We look at it as a glass half full even though we've got a lot of guys down. So does everybody else. We're excited to put a game plan together that gets the best out of all our guys."
He said Noel Devine, who played two games earlier this season, will likely dress as a running back and to help with kick returns, and Lavisier Tuinei will come off the practice roster to play receiver. They also have Bo Bowling on hand as a receiver and a returner.
Jennings, a big, power back, was impressive after Anderson was hurt in Toronto, carrying 10 times for 86 yards.
The Alouettes defence was key to the win in Toronto, led by linebacker Shea Emry who was named both top defensive player and best Canadian for the week by the CFL. Emry returned an interception 46 yards for Montreal's first defensive touchdown of the season.
The 9-6 team has already secured a home playoff date and can clinch first place in the East Division with one more win in its final three regular-season games.
The Alouettes don't want to repeat their late-season slide last year, when they lost their last three games to finish second to Winnipeg at 10-8.
"Finishing seasons is tough," said Trestman. ''The weather changes, everyone's edge is higher, everyone's fighting for positions.
"I don't know how this will unfold. We'll do our best to play hard every week."