In a season already plagued by injuries, the Kansas City Chiefs They suffered another cause for concern on Sunday against the Denver Broncos.

Early in the second quarter of Sunday’s divisional matchup, starting left tackle Wanya Morris exited the game after suffering an apparent right leg injury. Morris was watched by coaches on the sideline before “limping back to the Chiefs locker room.” according to Nate Taylor of The Athletic.

According to the team, it is officially questionable for Morris to return with a knee injury.

Update: After a long absence, Morris returned to left tackle in the fourth quarter. The story continues below as originally published.

When Morris exited, rookie second-round pick Kingsley Suamataia entered the game for Kansas City. Suamataia started KC’s first two games before being benched at the end of Week 2 against the Cincinatti Bengals.

After Morris’ injury, Jordan Foote of Kansas City Chiefs at SI reviewed Suamataia’s rookie season so far and explained why Suamataia might be feeling the pressure against Denver.

“Suamataia’s first few months in the NFL have been interesting, to say the least,” Foote wrote. “From the moment he was drafted, the overwhelming feeling was that not only would he have the opportunity to compete during the offseason, but he would receive a legitimate opportunity to play. He earned that right during training camp and the preseason, but he simply two short weeks into their regular season stretch, the Chiefs pulled the plug. Since Morris’ sample size quality wasn’t all that stellar, many (including Zack Eisen of Kansas City Chiefs at SI) defended the change to the rookie. That wish will be granted in week 10, albeit under unfortunate circumstances. “Now the pressure is on Suamataia to perform better than him to start his debut campaign and continue to grow as he goes.”

Read more: KC Chiefs vs. Denver Broncos injuries and inactives: Who’s in and who’s out for Week 10?