NASHVILLE, Tenn. -- Titans offensive coordinator Mike Heimerdinger left the team Wednesday and will undergo chemotherapy after a cancer diagnosis, coach Jeff Fisher said after practice.
The 58-year-old coordinator had not been feeling well for several weeks, but the team was taken aback by the development. Fisher declined to offer any further details.
"Mike is very sick," Fisher said. "And Mike is going to be, potentially as early as today, undergoing chemotherapy for cancer treatment. I don't know whether or not he'll be back [Thursday] or whether he'll be here inside the facility or whether or not he'll be able to participate in coaching this game."
The Titans were informed of the news just before practice, offensive lineman Jake Scott said.
The Titans concluded practice with a team prayer led by linebacker David Thornton.
"I'm not really good at saying or talking about things like that so thoughts and prayers go out to his family," receiver Randy Moss said. "Hopefully, his chemo and everything goes good, and we see him back as soon as he's ready."
Fisher said first-year quarterback coach Dowell Loggains and offensive line coach Mike Munchak will have input into the passing and running games, respectively. Loggains will likely call the plays while Fisher will maintain a close oversight, he said.
"We are going to continue with the game plan," Fisher said. "I will make sure this game will get called and the offense will be prepared. I just want everybody to keep Mike and his family in their prayers."
"It's life, you know," Fisher said. "We have to deal with it and we have to move on. Not that we're moving on from Mike. Mike's on my heart; he's been on my heart for weeks. What he's done over the last couple weeks, considering how he's felt, is absolutely remarkable. I mean, it's remarkable. Then you add the events of the weekend to that and it doesn't make sense.
"The Vince Young stuff is behind us," he said. "We're going to move on, get ready to play a football game and our guys are going to play hard."
Heimerdinger, 58, is in his second stint as the Titans' offensive coordinator. The man called "Dinger" was college roommates with Washington coach Mike Shanahan and helped coach Steve McNair to co-MVP of the NFL with Peyton Manning in 2003 during his first run as offensive coordinator in Tennessee before returning to the Titans in 2008.
He also spent 2005 as offensive coordinator of the New York Jets before returning to work with Shanahan in Denver as assistant head coach in 2006 and 2007.
Quarterback Kerry Collins said he's grown close to him over the past few years. Players knew Heimerdinger had been having some health issues but had worked through them the past couple weeks, not easing up on preparing the Titans to play. The players didn't get a chance to talk with Heimerdinger.
"He needs us right now. He needs us to be supportive," Collins said. "Obviously, all our thoughts and prayers are with him, and I know one thing about Dinger, the guy's a fighter. He's stubborn. He's tough. I know he's going to give everything he has to this fight, and I know he's going to get through it and be fine."
The Titans practiced indoors Wednesday due to rain. Seven players did not practice due to injuries including WR Kenny Britt, who has missed the past two games with a strained right hamstring. The others were TE Craig Stevens (knee), DT Jason Jones (right knee), DT Tony Brown (right knee), Collins (left calf), DE Dave Ball (concussion) and K Rob Bironas (right groin).
Paul Kuharsky covers the AFC South for ESPN.com. Information from The Associated Press contributed to this report.