Despite being five games over .500, things aren't going very smoothly for the Toronto Raptors. Their most glaring flaw is falling behind early in games; this past weekend against Sacramento, for example, they fell behind 37-18 after one quarter and were unable to dig out of the hole, losing 104-94. "It's terrible," said head coach Dwane Casey, who will be coaching against his former team on Tuesday night. "I mean it's totally unacceptable the way we performed (Sunday). Shame on us. The way you come into the game with that disposition of `OK, we're at home, we're OK.' It's not OK. How many times do we have to do that before it smacks us upside the head and wakes us up?" Toronto has also been bitten by the injury bug. Starters DeMarre Carroll (knee) and Jonas Valanciunas (hand) are both currently sidelined, although the latter recently returned to practice. Carroll should not be far behind either. One thing that the Raptors always do, however, is work hard. "Pound for pound, I don't know of another team in the NBA that plays harder than (the Raptors) on a consistent basis," said Dallas head coach Rick Carlisle. The Mavs have found success this season when someone steps up to compliment the ever-constant Dirk Nowitzki. Most recently, he's been helped by Charlie Villanueva and JaVale McGee coming off the bench. The Mavs are 5-1 when Villanueva reaches double-digits and will likely need his support in the second night of a back-to-back. The game will tip off at 7:30 tonight at the Air Canada Centre Tonight's @BICRazors projected starting lineups. pic.twitter.com/6A37WdjeE7 — Toronto Raptors (@Raptors) December 22, 2015 Photo: Dallas Mavericks' Dirk Nowitzki