Philadelphia 76ers forward Robert Covington is finalizing a four-year, $62 million contract extension, league sources told ESPN.

Sixers general manager Bryan Colangelo and Covington's representatives with CAA Sports are expecting a signed agreement as soon as the end of this week, league sources said.

The deal will include a $15 million renegotiation bump on Covington's $1.57 million salary this season, plus an additional four years that will keep Covington under contract through the 2021-22 season.

The $15 million renegotiation is the largest single-season figure negotiated since that became an available contractual avenue in the NBA.

Discussions on Covington's deal -- including the ability to formalize the renegotiation on his 2017-18 salary and the new extension -- became allowable on Wednesday under the league's collective bargaining agreement.

For the 76ers, the balloon payment on the 2017-18 season allows the team increased salary-cap space and payroll flexibility for upcoming seasons, when Philadelphia plans to be aggressive in free agency. The Sixers could have $25 million in salary-cap space this summer.