Dave Birkett

Detroit Free Press

Before he made his retirement official Tuesday, Calvin Johnson made one last play for the Detroit Lions, returning a portion of his signing bonus in order to give the team more salary cap room this year.

The Lions said in a statement released Tuesday that matters related to Johnson’s contract “were settled to the satisfaction of the parties.” They declined further comment today.

A person informed of Johnson’s payback told the Free Press that it was done ahead of the 2016 league year, and NFL Players Association records show that Johnson’s $12.9-million cap hit for this season was reduced by $320,000 for “return of (signing bonus) from retirement.”

Because Johnson retired four years after his last contract extension, the Lions could have recouped one-fifth of the $16-million signing bonus he received at the time, or $3.2 million. Bonus prorations are spread over up to five years of a player’s contract, for salary cap purposes.

Johnson paid back 10% of the $3.2 million, which was then credited back to the Lions’ cap.

In 1999, the Lions filed a grievance against Barry Sanders, seeking repayment of part of his signing bonus after the Hall of Fame running back retired early from the NFL. An arbitrator ruled that Sanders had to repay more than $5.5 million and forgo another $1.75 million of the $11-million signing bonus he received.

Sanders paid back the money in annual installments.

Johnson and the Lions avoided a similar dispute by negotiating a reduced payback some two months after Johnson first publicly acknowledged that he was considering retirement.

Johnson, who totaled more than $100 million in on-field earnings during his nine-year career, provided the Lions an additional $11 million in extra cap space by retiring before the 2016 league year started at 4 p.m. Wednesday.

The Lions, who entered free agency with about $42 million in cap space, have signed six players to contracts that total more than $18 million in first-year cap hits so far.

They entered today an estimated $25 million under the cap, with holes still to fill at safety, defensive end and on the offensive line.

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Contact Dave Birkett at dbirkett@freepress.com. Follow him on Twitter@davebirkett.

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Flashback: Mitch Albom column on Barry Sanders' retirement