It is the second such injury for Richardson, as he tore the ACL in the same knee during spring practice as a junior at Colorado in April 2012.
Richardson was the Seahawks’ top draft pick last May, taken with the 13th pick in the second round, 45th overall.
He suffered the injury in the third quarter of Saturday night’s 31-17 divisional-round victory over Carolina, trying to catch a deep pass from Wilson in the third quarter. He caught a 21-yard pass on the pervious play, his only catch in the game.
Late Saturday night in Seattle, before test results on the knee were back, Richardson tweeted the following:
The 22-year-old had only 29 catches for 271 yards and just one touchdown in the regular season, with only one catch for seven yards over Seattle’s first five games. His role in the offense increased after the Seahawks traded Percy Harvin to the Jets. Richardson’s final three regular-season games were his best, as he had five catches and eclipsed 50 yards in Weeks 16 and 17, and scored his only touchdown in a 17-7 win over San Francisco in Week 15.
With the recovery timetable for a torn ACL in the nine-month range, Richardson’s availability for the beginning of next season is also very much in the air.
"(It’s) a knee that he’s had worked on before, so we’ll see, we’re not sure," Seattle coach Pete Carroll told the media after the game but before the severity of the injury was known. "Sometimes you can’t tell on the tests right now."