The Milwaukee Bucks have agreed to a contract extension with Giannis Antetokounmpo, locking up one of the most versatile players in the NBA.

The Bucks announced the deal with the forward on Monday, and two people familiar with the agreement told The Associated Press that it was worth four years and $100 million. The people spoke to the AP on condition of anonymity because the team's announcement did not include terms.

Yahoo Sports first reported details of the extension.

The 6-foot-11 Antetokounmpo averaged 16.9 points, 7.7 rebounds and 4.3 assists last season, his third in the league. With his length and versatility, he has turned into a matchup nightmare for opponents.

The Bucks see Antetokounmpo and forward Jabari Parker as the building blocks of an emerging franchise. The deal ensures Antetokounmpo will be under contract in 2018, when the team is scheduled open a new downtown arena.

Antetokounmpo has improved steadily since being drafted in the first round of the 2013 draft with the 15th overall pick, considered a project out of Greece.

Milwaukee missed the playoffs last season after making a surprise run in 2014-15. But Antetokounmpo blossomed after taking over ball-handling duties late last season, becoming the first player in franchise history to record five triple-doubles in a season.

The Bucks open training camp next week in Madison, Wisconsin.

"In my fourth year, my role is going to be a lot bigger," Antetokounmpo said in April. "It's time for me to step up and lead this team."