The Memphis Grizzlies have exercised their third-year options on contracts for Jaren Jackson Jr. and guard Grayson Allen.

The Grizzlies announced the moves Monday.

Jackson was the fourth overall draft pick in 2018, and he averaged 13.8 points and 4.7 rebounds in 58 games to earn NBA All-Rookie First Team honors. At 19, Jackson was the second-youngest player in the NBA last season. He turned 20 last month.

The Grizzlies acquired Allen in a trade with Utah that sent Mike Conley to the Jazz this summer. The 6-foot-3 Allen was the 21st overall pick in 2018 after playing four years at Duke. He averaged 5.6 point in 38 games for Utah and had a career-high 40 points against the Clippers on April 2, the second-highest scoring game by a rookie last season.