The Phoenix Suns are extending sharpshooter Grayson Allen on a four-year, $70-million deal with a player option, his agents told ESPN's Adrian Wojnarowski.

Allen had a career-best regular season, averaging 13.5 points per game while leading the league in 3-point percentage at 46.1%. He's now hit at least 39% of his threes in five straight seasons.

The Duke product joined Phoenix in the offseason as part of the blockbuster Damian Lillard trade. He's provided elite spacing next to the Big Three of Kevin Durant, Devin Booker, and Bradley Beal.

Allen will play a major role in the playoffs for the sixth-seeded Suns, beginning in the first round against the Minnesota Timberwolves.

The 28-year-old is arguably Phoenix's biggest X-factor - the team is 7-2 when he makes at least six 3-pointers in a game.