Injured Raonic out of Canada Davis Cup tie

Canada have been severely weakened for their Davis Cup World Group tie against Japan in Tokyo by the withdrawal of Milos Raonic with a foot injury.

Milos Raonic has pulled out of Canada's David Cup World Group tie against Japan with a foot injury. (AAP)

Milos Raonic has pulled out of Canada's Davis Cup World Group tie against Japan with of a left foot injury.

Raonic, who withdrew on Thursday, will be replaced by Peter Polansky who was in Tokyo as a reserve but will be counted on heavily.

Polansky will face a tough task in the opening singles rubber on Friday against world No.18 Kei Nishikori.

Nishikori will be looking to improve on his four-match Davis Cup winning streak and an overall 10-2 singles record in the team tournament.

Frank Dancevic, a 29-year-old veteran of 19 Davis Cup ties, will face Go Soeda in Friday's other singles rubber at Ariake Colosseum.