The Washington Mystics re-signed reigning MVP Elena Delle Donne to a four-year contract on Tuesday, coach and general manager Mike Thibault announced.

Delle Donne was an unrestricted free agent. Financial terms of the deal were not disclosed.

The star forward was selected as an All-Star for the sixth time in 2019 and led the Mystics to their first WNBA championship.

"Elena is the most impactful player in the history of the Washington Mystics and her commitment to us three years ago set the stage for us to make our championship run possible," Thibault said in a statement. "I am thrilled that she has signed with us for four more years and will lead us as we continue to build on the culture of excellence that we have established here in D.C."

Delle Donne averaged 19.5 points and a career-best 8.3 rebounds per game last season. She shot 51.5% from the field and 43.0% from 3-point range en route to her second straight All-WNBA First Team selection.

"Last year bringing a Mystics championship home to D.C. was beyond special. The fans who supported us, and the closeness we had as a team, how hard we all worked together led to an incredible outcome," Delle Donne said in a statement. "(Owner) Ted (Leonsis) and (managing partner) Sheila (Johnson) sowed the seeds for this. They have built an amazing organization, and they along with my teammates, Coach Thibault and his coaching staff, and everyone at the Mystics welcomed me and Amanda with open arms and made this our home. I'm thrilled to be returning for another four years and look forward to defending our title this season in front of the best fans in the world."

She is entering her fourth season with Washington after playing for the Chicago Sky, for whom she was the WNBA MVP in 2015.

Delle Donne is expected to be ready for the start of the season in May after having back surgery last month.

The Associated Press contributed to this report.