Toronto Raptors (1-3) at Dallas Mavericks (3-1), 8:30 p.m.

(Sports Network) - The Dallas Mavericks are thriving without star forward Dirk Nowitzki and will try for win No. 4 in this early part of the season tonight when they host the Toronto Raptors.

The Mavericks walloped the Portland Trail Blazers, 114-91, on Monday night as guard O.J. Mayo went off again. Celebrating his 25th birthday, Mayo torched the Blazers for 32 points on 12-for-18 shooting.

Mayo, who was signed as a free-agent in the offseason, had 30 against the Charlotte Bobcats on Saturday night. He went 10-for-17 from the field that night, but more impressively, 7-for-10 from the 3-point line.

"It's just being prepared to shoot," said Mayo. "We're getting better with finding one another, so obviously with Darren (Collison) getting in the paint or (Brandan) Wright, Chris (Kaman) and Vince (Carter), I'm just trying to be locked and loaded. The good thing is that we won both games. That's the most important thing."

Mayo and company may need to keep it up. Another prominent Maverick, forward Shawn Marion, will be out of action the next three games with a sprained medial collateral ligament in his left knee.

Mayo is doing the heavy lifting now, but it has been a team effort for Dallas. Collison is averaging 16.5 points and 8.5 assists and Kaman and Carter are putting up big scoring numbers off the bench.

The Raptors suffered a 20-point loss last night to the Oklahoma City Thunder, but the bigger loss came in the form of point guard Kyle Lowry. The point guard, who averaged 23.7 points, 7.3 rebounds and 7.0 assists over Toronto's first three outings, sprained his right ankle in the second half last night and he is questionable tonight.

Jose Calderon would start in his place.

"Jose is a veteran player and he'll be ready to go," coach Dwane Casey said Tuesday night. "That's why I kept his minutes to a minimum tonight. He'll have to play big minutes and John (Lucas III) is a capable point guard, so they'll have to be ready to go. Knowing Kyle, he's a tough guy and he'll get back as soon as he can."

A real, and probably lone, bright spot for the Raptors last night was the play of rookie center Jonas Valanciunas. He posted a career-high 18 points and Andrea Bargnani had 16 in the losing effort.

The foreign big men were the only two Raptors' starters in double figures last night. DeMarr DeRozan only managed eight points on 2-for-10 shooting.

The Mavericks, who will try to go 4-1 for the first time since the 2007-08 season, have won five of the last seven against the Raptors. Toronto is winless in 11 of its last 12 trips to Big D.