Packers coach Mike McCarthy believes that Nelson's hamstring injury is not serious but acknowledged that the star wide receiver will "be pressed hard" to play against the Lions.
"I don't know how many weeks Jordy would be out," McCarthy said Monday. "I think he would be pressed hard to play this week. Once we get past the initial couple days and see what he can do on the practice field, those questions will be answered."
Nelson aggravated his hamstring during pregame warmups in this past Sunday's victory over the Minnesota Vikings. He attempted to play through the injury but ultimately left after Green Bay's second drive of the game.
Nelson, who missed a game earlier this season due to the hamstring injury, is Green Bay's second-leading receiver with 46 catches for 658 yards and six touchdowns.
McCarthy also said that starting right tackle T.J. Lang, who left Sunday's game due to an ankle injury, was uncertain to play against Detroit.
"I feel probably a little bit better about T.J. than I do about Jordy," McCarthy said.
Information from The Associated Press was used in this report.