WASHINGTON -- Marcin Gortat has signed his five-year, $60 million contract to remain with the Washington Wizards.

The Wizards announced Thursday that the Polish center had signed the deal on the first day permitted under NBA free-agency rules.

Gortat posted a picture of himself signing the papers on his Twitter page, writing that it was the best day of his life.

Gortat agreed to the deal on July 1, reaffirming his desire to remain with the Wizards after helping lead the club to its first playoff berth since 2008.

Gortat averaged 13.2 points and a team-leading 9.5 rebounds after he was acquired in a preseason trade with the Phoenix Suns.

The Associated Press contributed to this report.