Detroit Lions running back Jahvid Best is unlikely to play against the Chicago Bears on Sunday as he continues to recover from his most recent concussion, a league source told ESPN NFL Insider Adam Schefter.
Best, who has dealt with concussions dating back to college, is scheduled to meet with more doctors this week and will undergo further testing, the source said.
Best has not played since experiencing concussion-like symptoms following Detroit's Week 6 loss to San Francisco.
Without Best, Detroit has gone to a running-back-by-committee look, deploying veteran Maurice Morris and second-year player Keiland Williams almost equally. The duo has rushed for 177 yards and one touchdown.
Detroit (6-2) is coming off a bye week and added former third-round draft pick Kevin Smith on Tuesday to a backfield that's also missing Jerome Harrison and rookie Mikel Leshoure. Harrison is out for the season after being diagnosed with a brain tumor and Leshoure ruptured his Achilles tendon.
Information from The Associated Press contributed to this report.