Former UFC lightweight Kevin Lee's preparation for his return to action this year recently took a painful turn in the form of a full-power right hand from a sparring partner.

Lee, who unsuccessfully challenged for interim gold in the UFC back in 2017, has struggled in recent years. He's won just two fights since 2019, both of which came away from the Octagon.

After defeating Diego Sanchez in Eagle FC following his first UFC release, "The Motown Phenom" was choked unconscious in under a minute by Rinat Fakhretdinov in his return to MMA's biggest stage. While he bounced back with a regional victory last September, Lee's pleas for another UFC comeback fell on deaf ears.

As a result, Lee has sought a different opportunity, and that landed him in the inaugural Global Fight League draft last month. The 32-year-old was picked by New York City, joining Sidney Outlaw as the team's two lightweights.

With that, "The Motown Phenom" is putting the work in at Kill Cliff FC in Florida ahead of his new venture. But it would seem that not everything has been going to plan for the veteran fighter on the mats.

Footage emerged this week showing Lee suffer a bad knockdown in training. After throwing a flying knee, the ex-UFC fighter's sparring partner landed a full-strength right hand that briefly put the Michigan native down.

Overseeing the session was former UFC champion Robbie Lawler, who sported a concerned face as he helped an unsteady Lee back to his feet.

The video was recorded and posted to Instagram by undefeated Azerbaijani fighter Maggeram Gasanzade.

It's believed the punch was thrown by Mirali Huseynov, another Azerbaijani athlete who has a 9-3 record as a professional. His last two wins have come under the banner of Urijah Faber's A1 Combat. Huseynov appeared in the comments section of a repost to request the video be taken down.

The clip drew plenty of reactions online, with the community surprisingly split on who was to blame. While many slammed Huseynov for throwing at full capacity, others criticized Lee for the flying knee attempt.