Two Lions players shared news of Thursday surgeries on social media.
Running back Joique Bell posted a photo on Instagram of himself in a hospital bed, though it's unclear the reason for his operation.
"Surgery was a success, be right back like I left something #Concrete," Bell wrote.
Offensive tackle LaAdrian Waddle informed the public of his operation on Twitter. Waddle finished the 2014 on injured reserve after suffering a left knee injury in Week 15.
"Started my last 2 classes to graduate from @TexasTech today and having surgery tomorrow," Waddle wrote Wednesday.
The Lions listed Bell on the injury report in Week 17 with an Achilles injury, but he was limited just one day before being a full participant the next two days. He also dealt with knee and ankle injuries during the season.
If Bell was injured, it didn't show in his play as he established himself as the top runner in the Lions' backfield in 2014. In the second half of the season, Bell ran for 547 yards and scored five total touchdowns. He also averaged at least 4 yards per carry in seven of the final eight games and gained 85 yards from scrimmage in the Lions' playoff loss to the Dallas Cowboys.
Bell posted something similar last year after an offseason knee surgery, but later denied that he underwent an operation.