As the 2021 NFL regular season is inching closer and closer, the Buffalo Bills are already facing one noteworthy injury dilemma.

Bills wide receiver Stefon Diggs was a notable absence in practice on Sunday.

Bills head coach Sean McDermott noted that Diggs was held out of practice due to his lingering knee injury, which also forced him to miss the team's preseason opener against the Detroit Lions.

McDermott did add that for the moment, there is no major concern that Diggs may miss the Bills' regular season opener, which will come with a home clash against the Pittsburgh Steelers.

Diggs has already missed multiple practices as of late due to this injury, including being held out of last Monday's practice as a mere precaution.

It is not known just when Diggs may receive the green light to return to practice. At the least, the Bills' coaching staff will be keeping a close watch on his progress from this minor knee issue, as the team aims to have him avoid any major setbacks along the way.

Diggs is coming off of a standout season in his debut campaign with the Bills, where he helped revamp the team's deep passing attack alongside starting quarterback Josh Allen. He led the league in receptions (127) and receiving yards (1,535) en route to being selected to the All-Pro first-team for the first time in his career.

For now, all eyes will be on Diggs' injury progress over this week.