Best, who was selected NFL Rookie of the Month on Thursday, has a turf toe injury on his right foot. Levy has groin and ankle injuries.
"It's been getting better so far, and it's looking like I'll be able to go this week," Best said. "So far, I'm going to give it a go tomorrow and see how it feels. But it's gotten a lot better than I thought it was going to get. It's looking real good right now."
When asked he would be able to play Sunday, Best replied, "Oh yeah, definitely."
Best leads the Lions in rushing (124 yards), receiving (16 catches for 183 yards) and touchdowns (five).
The Lions also announced the signing of safety Dante Wesley and the release of safety Randy Phillips on Thursday.
Detroit cut Wesley when setting its 53-man roster earlier in September. He has played primarily on special teams in his eight seasons, seven with the Carolina Panthers.
The Associated Press contributed to this report.