Lawson agreed Sunday with the Mavericks on a standard NBA contract, Adrian Wojnarowski of ESPN reports.
Lawson ended Saturday's 144-119 win over the Spurs with 17 points (7-10 FG, 3-4 3Pt), seven rebounds, three assists and two steals over 31 minutes.
Lawson had 12 points (5-9 FG, 2-6 3Pt) and six rebounds in 23 minutes during Friday's 115-112 loss to Chicago.
Lawson hasn't appeared in any games for the G League's Texas Legends since Feb. 25 due to a right knee injury.
Lawson finished Wednesday's 118-109 loss to the Nuggets with 10 points (4-6 FG, 2-3 3Pt), two rebounds and one steal in 12 minutes.
Lawson tallied 28 points (12-20 FG, 4-7 3Pt), 13 rebounds, four assists and three steals in 37 minutes Saturday's 121-117 win over the Blue.
The Mavericks signed Lawson to a two-way contract on Monday, Shams Charania of The Athletic reports.
Lawson posted 22 points (5-14 FG, 1-6 3Pt, 5-7 FT), five rebounds, two steals and one assist in 37 minutes during Tuesday's 120-104 loss to the Charge in the G League Showcase.
Lawson posted 32 points (14-21 FG, 4-7 3Pt, 0-3 FT), nine rebounds, three steals and two assists in 37 minutes during Friday's 134-116 win over Raptors 905.
Lawson posted 23 points (9-15 FG, 1-5 3Pt, 2-4 FT), five rebounds, three assists and one steal in 33 minutes during Monday's 127-119 win over Delaware.