Baltimore Ravens running back Kenneth Dixon had knee surgery on Tuesday to repair a medial meniscus. According to the team, there is no timetable yet for his return.
But two sources tell ESPN's Adam Schefter it's 50-50 that Dixon is out for the year. Another source tells Schefter that a four- to five-month recovery is expected, so a return is possible but unlikely.
Sources tell Schefter that the team will have more discussions Wednesday to determine a timetable.
Dixon was already suspended for the first four games of the regular season for violating the NFL's policy on performance-enhancing drugs. Baltimore is looking to sign Bobby Rainey to help with depth at running back.
This is Dixon's third knee injury in 12 months. Dixon strained the MCL in his left knee on the first day of training camp last year, and he sprained the MCL in the same knee during the preseason.
Dixon, a fourth-round pick from a year ago, showed flashes last season in breaking tackles and finishing second on the team with 382 yards rushing.
The NFL Network reported the surgery would end Dixon's season.
ESPN's Jamison Hensley contributed to this report.