Houston Rockets center Alperen Sengun has agreed on a five-year, $185 million rookie extension, his agents Sean Kennedy and Jeff Schwartz of Excel Basketball told ESPN's Bobby Marks.

The contract includes a player option in the last year.

The deal comes ahead of a 6 p.m. ET deadline for rookie extensions. Sengun becomes the first player to sign a five-year rookie extension and have a player option since Luka Doncic and Trae Young.

Sengun, 22, blossomed into an All-Star candidate last season -- and earned a third-place finish in Most Improved Player voting -- by averaging 21.3 points, 9.3 rebounds and 5 assists per game for Houston before his season was cut short by an ankle injury.

He was one of just six players to average at least 21, 9 and 5 last season, with the others being Doncic, Nikola Jokic, Giannis Antetokounmpo, Joel Embiid and Julius Randle.

Sengun was taken with the 16th pick in the 2021 NBA draft by the Oklahoma City Thunder -- with a pick that originally belonged to the Boston Celtics as part of the deal that sent Kemba Walker to OKC in exchange for Al Horford -- before immediately being rerouted to the Rockets.

He joins Jalen Green, who also agreed to a three-year, $106 million deal on Monday, as members of the 2021 class the Rockets have secured long term.

ESPN's Tim Bontemps contributed to this report.