OSAKA -- Yokozuna Takanohana will sit out an unprecedented fifth straight tournament as a grand champion of sumo with the daunting prospect that a prolonged knee injury could signal the end to his illustrious career.

Takanohana, who injured his knee in last May's summer tourney, will submit an application to withdraw from the 15-day spring meet to the sumo pairings committee on Friday, sumo sources said Thursday.

But more than being able to make an appearance in the Spring Grand Sumo Tournament that gets under way in Osaka on Sunday, Takanohana is more concerned about whether he will ever be able to wrestle again. "Right now, I'm thinking about what's going to happen to my knee and I know it hasn't completely healed yet. It could be that it is all over for me," Takanohana said after putting in a series of light workouts at the start of the year.

Though he said "I came to Osaka to wrestle," Takanohana has shown little enthusiasm in his practices since January and his recovery has been slower than expected. With the withdrawal from the spring tourney, he becomes the owner of the worst mark -- with five successive absences -- as a yokozuna since Onokuni back in 1925.