Finney-Smith has developed into a quality role player since joining the Mavericks as an undrafted rookie three years ago. He averaged 7.5 points and 4.8 rebounds in 24.5 minutes per game last season and is one of Dallas' best perimeter defender.
The Mavs still have more than $22 million in salary-cap space and hope to sign Danny Green, according to sources. Green is waiting for two-time title teammate Kawhi Leonard to make his free-agency decision before determining whether he will accept Dallas' offer.
The Athletic first reported Finney-Smith's deal.