The Minnesota Timberwolves are keen to lock up guard Andrew Wiggins to ensure he is a cornerstone for their future.

Wiggins and the Timberwolves are engaged in contract negotiations on a five-year extension that would be worth nearly $148 million, according to Timberwolves coach and president of basketball operations Tom Thibodeau.

"We're working on it right now," Thibodeau said Wednesday during a news conference to introduce Jamal Crawford.

Under the collective bargaining agreement, NBA teams can have two players on designated rookie-scale extensions. Such deals must be agreed to by one day before the start of the season.

The extension would take effect in 2018-19, with a starting salary of $25.5 million that season. The sides could agree to terms where, if Wiggins made an All-NBA team or was named Defensive Player of the Year in 2017-18, that figure would jump to $30.6 million.

The Timberwolves are in talks with Andrew Wiggins that could tie the guard to the team for five years. AP Photo/Andy Clayton-King

Wiggins, 22, set career highs in points (23.6 PPG) and assists (2.3 APG) last season. He has started all but one game for Minnesota over the past three seasons.

Last week, Thibodeau told ESPN that Wiggins' goal for the 2017-18 season should be to become a "complete player" and said trade acquisition Jimmy Butler could help with that development.

Beyond Wiggins' long-term deal, the Timberwolves also want to sign two wing players and a backup point guard during the offseason to fill out their roster.

"There are a number of guys we're talking to, and they're waiting," Thibodeau said. "So you're trying to weigh all that out. It'll be interesting to see everything unfold."

ESPN's Bobby Marks contributed to this report.