The Pittsburgh Steelers and Le'Veon Bell failed to reach an agreement on a contract extension before Monday's 4 p.m. ET franchise tag deadline, and his agent said that means this likely will be the running back's final season with the team.

"His intention was to retire as a Steeler," Adisa Bakari told ESPN's Adam Schefter. "But now that there's no deal, the practical reality is this now likely will be Le'Veon's last season as a Steeler."

Bell will play under the franchise tag for the second consecutive year, barring an unforeseen development. He tweeted after Monday's deadline passed that "2018 will be my best season to date." The tentative plan is for Bell to skip training camp but be ready for the start of the season, Bakari told SiriusXM NFL Radio on Tuesday.

to all my Steeler fans, my desire always has been to retire a Steeler...both sides worked extremely hard today to make that happen, but the NFL is a hard business at times...to the fans that had hope, I'm sorry we let youu down but trust me, 2018 will be my best season to date... — Le'Veon Bell (@LeVeonBell) July 16, 2018

The parties reopened negotiations last week and talked throughout Monday, hoping to spark something, but there hasn't been much momentum toward a contract over the past few months.

"It became clear the Steelers wanted to pay the position, not the player," Bakari said.

The Bell negotiation was one of the most complicated in recent Steelers history because of Bell's leverage under the franchise tag, a sagging running back market and Bell's conviction to be paid as one of the game's best playmakers, regardless of position. It has been more than 500 days since the Steelers first tagged Bell at $12.1 million on Feb. 27, 2017.

"Even though we could not reach a long-term contract agreement with Le'Veon Bell, we are excited he will be with the team in 2018," Steelers general manager Kevin Colbert said in a statement. "We worked very hard to find common ground, but we were unable to accomplish that prior to today's deadline. Le'Veon will play this season under the exclusive franchise tag designation.

"After the 2018 season is completed, we again will attempt to work out a long-term contract with Le'Veon in the hope that he will continue his career with the Pittsburgh Steelers."

The Steelers made two sizable contract offers -- one last summer and one this winter -- beginning at around $13.3 million per year on average and working their way up slightly. Bell turned both of them down, telling ESPN in April that he wouldn't take a contract worth less than $14.5 million annually, based on the amount of his 2018 tag number. For months after that, negotiations lacked real momentum.

The Steelers felt their offers were good and didn't want to overinflate the salary for a position that hasn't landed a long-term deal worth more than $10 million per year since Chris Johnson and Adrian Peterson in 2011.

With that in mind, Bell knew he could play out two franchise tags worth a combined $26.62 million and have a chance at true free agency as a 27-year-old in 2019, setting the stage for peers Todd Gurley and Ezekiel Elliott in future years.

The Bell saga twisted unexpectedly in January, when the star back told ESPN that he would consider retirement if asked to play on the tag for the second straight year. He has since softened that stance, though he hinted at missing a second straight training camp in absence of a long-term deal.

"Just get the numbers straight, exactly where we want them," Bell said then. "I'm not going to settle for anything. I know what I do and what I bring to the table. I'm not going out here getting the ball 400 times if I'm not getting what I feel I'm valued at."

Bell didn't sign last season's tag until Sept. 4 and showed some rust with 3.46 yards per carry through the first three weeks. But he finished the year as an All-Pro, rushing 321 times for 1,291 yards along with 85 catches for 655 yards and 11 total touchdowns.

He has 7,996 yards from scrimmage through 62 career regular-season games, the most of any NFL player in that span since the 1970 AFL-NFL merger, outdistancing Eric Dickerson (7,842), according to ESPN Stats & Information.

"It became clear the Steelers wanted to pay the position, not the player," Le'Veon Bell's agent said of the two sides' failure to reach an agreement. Bell will play on the franchise tag for the second consecutive year, barring an unforeseen development. Kevin C. Cox/Getty Images

After the season, Colbert told Bell that the team wanted him to retire a Steeler. Team president Art Rooney echoed the sentiment in an end-of-year interview with local media.

Despite both sides wanting to finish a contract, Steelers players got used to life without Bell. They want him to get paid but also want him on the field with them.

"I think last year a lot of guys were like, 'Oh, Le'Veon's not here,'" wide receiver Darrius Heyward-Bey said during offseason workouts. "Nobody cares. We're out here, and we have to get work done. ... We'll see him when we see him. Next man up."

Added safety Morgan Burnett: "You definitely understand because it's definitely a business. Within your career, it seems long, but it's only a short period of your life. So the stuff you accomplish, the money you make within this time, you want to find a way to make it expand the rest of your life."

The Steelers report to Saint Vincent College in Latrobe, Pennsylvania, for training camp on July 25. Bell has used boxing and a vegan diet this offseason to stay in shape, holding off from most football exercises to keep his knees fresh.

Asked about the likelihood of Bell missing camp, Steelers guard David DeCastro said, "We'll see him when he gets here. You can't worry about guys who aren't here. It is what it is.

"You wish he was here. What can you do? It's a business."

Steelers wide receiver Antonio Brown was asked his reaction to Bell failing to get a long-term deal signed.

"To each his own. He needs to take care of his business," Brown told ESPN's Josina Anderson. "We'll welcome him when he comes and decides to move forward for 2018.

"He'll play pissed off, extremely motivated, super hungry, [in] crazy condition and ready to show why he deserves to be paid like the best."