A team source told ESPN's Chris Mortensen the team is not optimistic a deal will happen before training camp begins Monday. Veterans are scheduled to report Sunday.
Suh's contract negotiations have been one of the biggest issues for the Lions this offseason. Due to restructuring on his original rookie contract, he is due $22.4 million against the salary cap this season. Furthermore, if the Lions are unable to re-sign him, they would have to decide whether to use the franchise tag on him for the 2015 season, which would come at a cost of $26.7 million.
This is the first shift in the Lions' stance toward being able to bring back Suh. Throughout the first few months of the offseason, both team president Tom Lewand and general manager Martin Mayhew expressed confidence they would be able to sign Suh to an extension and also said Suh indicated to them he wanted to remain in Detroit.
"Ndamukong has said he wants to stay and we want him to stay," Lewand said in March. "Generally when that happens, you can get a deal in place."
Lewand's statements came a few weeks after Mayhew said at the NFL scouting combine he anticipated a deal being finalized with Suh on "the eve of the start of the new league year, which is when free agency starts or some time shortly after the start of the new league year." Neither one of those things has happened.
One of the initial complications in reaching a deal with Suh was a change in his representation. He fired Relativity Sports, which negotiated his first contract, in January. Almost two months later, he signed with one of the top agents in the NFL, Jimmy Sexton.
Suh appeared to back up Mayhew and Lewand's claims the lone time he spoke about his upcoming contract situation, saying he chose to come to Detroit when he was selected with the No. 2 pick in the 2010 draft.
"I think I said this from the very, very first day I got drafted," Suh said in May. "I'm here for a reason. I had an opportunity, probably a lot of you guys don't know, could have gone elsewhere when I was drafted. I had that decision in my hands -- I chose not to take because that's just the way I saw it. The same thing when I went to Nebraska. I wanted to be a part of something that wasn't just already set up or on its way to getting better, and I want to be one of the cornerstones of it.
"That's what I see myself in Detroit, being one of the cornerstones, getting this organization back to a championship level and like Coach Caldwell said, we're not in a rebuilding year, we're in a year of going to get a championship and that's what I want to be here for."
Suh has been a major piece of Detroit's defense since 2010. He has played in 62 games for the Lions, registering 185 tackles along with 27.5 sacks. He has often faced double teams throughout his four years in the league, and Lewand said in March they built their defense around a strong defensive line. Suh is the anchor to that.