KANSAS CITY, Mo. -- To illustrate the scope of the rebuilding job on the offensive line, the Kansas City Chiefs in recent days have signed three free agents, including one of their own, and are preparing for the return of two players who opted out of last season.

And they still have work to do before finishing the job.

The Chiefs made overhauling their offensive line a priority this offseason after quarterback Patrick Mahomes was constantly pressured by the Tampa Bay Buccaneers during the Super Bowl. The Chiefs haven't wasted time, signing guards Joe Thuney and Kyle Long and re-signing Mike Remmers, who played at both guard and tackle last season.

They still have no obvious candidate to start at left tackle and no one with starting experience to start at center. Eric Fisher, the Chiefs' longtime starting left tackle, was recently released after having surgery for a torn Achilles tendon but could eventually be re-signed.

The Chiefs do have more than enough candidates to start at guard, including Thuney, Long, Laurent Duvernay-Tardif, Andrew Wylie and Nick Allegretti. Duvernay-Tardif, a former starter, opted out last season because of COVID-19. Wylie and Allegretti were the starting guards for most of last season.

Long and Thuney have played their careers mostly at guard, but Long was a right tackle for one season for the Chicago Bears, in 2015, and made the Pro Bowl that year. Thuney filled in at center last season for the New England Patriots.

Each said he would be open to switching positions.

"I'm comfortable with anywhere on the offensive line," Long said. "I've never played center. I'm left-handed. I don't know many left-handed centers, but I'm open to learning anything."

Thuney said, "I just want to help the team wherever I can, in any capacity. I just want to contribute to winning and that's really my main thing, so wherever that is, that's fine with me.”

The Chiefs in their free-agent search for linemen were interested as much in good players as positions. Thuney, who didn't miss a start in his five seasons with the Patriots, agreed to contract terms with the Chiefs shortly after the negotiating period began.

"Joe is an impressive player," Chiefs coach Andy Reid said. "He's everything you want in an offensive lineman with his toughness and work ethic. He's also very intelligent and you can see that translate on the field."

Long made the Pro Bowl in each of his first three NFL seasons with the Bears. He hasn't played a full season since 2015 because of injuries, and he said he sat out last season to get his body right. All the while, he was preparing for his eventual return.

"It was a tremendous opportunity for me to regain physical, mental, emotional composure, get my feet back under me," Long said.

"I knew right away when I was let go in Chicago that I would be back, and I needed to do everything in my power to get myself back to where I knew I could come in and play the level of football I know I can play."