Portland Trail Blazers guard CJ McCollum has agreed to a three-year, $100 million contract extension, extending his current deal to five years and $157 million, his agent, Sam Goldfeder of Excel Sports, told ESPN.

The new deal will start with the 2021-22 season.

McCollum became eligible for the extension on Saturday and joins All-NBA teammate Damian Lillard in landing summer deals that solidify the Blazers' backcourt into the mid-2020s.

Goldfeder and Blazers president of basketball operations Neil Olshey completed the agreement on Tuesday.

"CJ McCollum is a franchise cornerstone and a critical part of our future," Olshey said. "This extension represents a strong level of commitment between CJ, the Trail Blazers and the city of Portland."

McCollum, 27, has been one of the anchors of the Blazers' success in recent seasons, including two trips to the Western Conference semifinals and last season's berth in the conference finals.

McCollum was eligible to negotiate the extension beginning on July 27 -- the third anniversary of his signing a four-year, $106 million extension.

He averaged 21 points in each of the last two regular seasons and 25.3 and 24.7 points, respectively, in the playoffs. McCollum, the 10th overall pick in the 2013 draft, was voted the NBA's Most Improved Player in 2016.

The Blazers signed Lillard to a four-year, $196 million extension this summer, keeping him under contract through the 2025 season.