The Minnesota Vikings have informed running back Dalvin Cook that they plan to release him, a source told ESPN's Adam Schefter on Thursday.

The Vikings are expected to try to trade Cook one more time Thursday, and if they are unable to, they plan to process his release Friday, according to a source. Either way, this will bring an end to Cook's six-year tenure in Minnesota.

The Miami Dolphins are expected to have an interest in signing Cook once he is released, sources told Schefter.

Cook, who turns 28 in August, was set to take up $14.1 million in cap space for 2023 and was due to earn $11 million if he spent the season with the Vikings. Those are big numbers for an aging running back who surpassed 1,500 touches in his career last season.

The Vikings would owe Cook $2 million if they release him. By doing so after June 1, the Vikings would save $9 million in cap space while taking on $5.1 million in dead money on their 2023 cap.

Dolphins coach Mike McDaniel declined to comment about Cook's expected availability when asked Thursday and complimented his current group of running backs, which includes veterans Raheem Mostert, Jeff Wilson Jr. and Myles Gaskin and rookie Devon Achane.

"Overall, very happy with the way they've practiced, very happy with their competitive camaraderie," McDaniel said. "They are all trying to be the best, but they're not doing it in spite of each other and they recognize that each one of them can help them get better, so it's been a cool camp for them."

The long-rumored split seemed certain after the Vikings re-signed Cook's longtime backup, Alexander Mattison, to a contract that included $6.35 million in full guarantees over the next few seasons. Given multiple opportunities after that move, general manager Kwesi Adofo-Mensah refused to speculate on whether Cook would be on the Vikings' 2023 roster.

Mattison is expected to take over as the team's primary tailback, with 2022 backups Kene Nwangwu and Ty Chandler -- and possibly rookie DeWayne McBride -- competing for the No. 2 role. Vikings coach Kevin O'Connell said last month during organized team activities that Mattison has been demonstrating "that all-three-down kind of ownership that he's been capable of for a long time."

Cook, a second-round draft pick in 2017, struggled to stay on the field for much of the early part of his career in Minnesota. His rookie season ended after four games because of a torn ACL, and an assortment of other injuries cost him between two and five games in each of the next four seasons. A chronic shoulder injury ultimately forced him to wear a harness for long stretches of his career.

He nevertheless managed to produce four consecutive 1,000-yard seasons between 2019 to 2022 and scored a combined 29 rushing touchdowns during the 2019 and 2020 seasons. He also proved to be an effective receiver, averaging 42 receptions per season after his rookie year.

Cook managed to start every game in 2022 for the first time in his career, even after separating his shoulder in Week 3. But he finished with an average of 17.8 touches and 86 yards from scrimmage per game in O'Connell's new scheme -- both the lowest since he became a full-time player in 2019.

He did knock off two of the six longest runs of his career in 2022: a 53-yard score in Week 6 against the Miami Dolphins and an 81-yard touchdown in Week 10 against the Buffalo Bills. On the latter, he recorded a top speed of 21.68 mph, according to NFL Next Gen Stats, the seventh-fastest speed of any ball carrier in 2022.

But his efficiency numbers, which measure the frequency of carries that produce a positive outcome, dipped noticeably. He led the NFL with 62 carries that either lost or did not gain a yard. And as ESPN's Bill Barnwell noted, only 34.5% of his carries gained a positive total of yards over expectation in Next Gen Stats' model, the second-lowest rate among running backs with at least 200 carries in 2022.

Cook underwent shoulder surgery Feb. 14 in hopes of avoiding the chronic separations he has had. At the time, the Vikings said he would be fully recovered in time for the regular season. He had not been participating in the voluntary portion of the Vikings' offseason program, and the timing of his departure means there will be no clash over whether he reports for mandatory minicamp later this month.