Green Bay Packers running back Eddie Lacy has confirmed that he left the field due to an asthma attack rather than an injury on Sunday.

There was concern for Lacy as he exited the tie with the Minnesota Vikings during the overtime period, having rushed for 110 yards and a touchdown before his respiratory problem kicked in.

Lacy told JS Online.com: "It's worse in the winter time I've had it since I was little.

"Sometimes it's worse than others. And it's going to get worse, I think, with the cold weather we'll be having."

That it wasn't a serious injury to Lacy will be good news to the Packers, who are still in the playoff hunt in the NFC North.