Sources: Dwane Casey Raptors' favorite

Dallas Mavericks assistant coach Dwane Casey has emerged as the clear favorite to land the Toronto Raptors' coaching job and could be installed as the team's new coach by next week, according to sources close to the situation.

The Raptors began the week having narrowed their search for a successor to Jay Triano down to the former Minnesota Timberwolves coach and Boston Celtics assistant coach Lawrence Frank. But Toronto has since zeroed in on Casey after interviews with both men this week, drawn largely to Casey's success as the defensive coordinator for a Mavericks team that just won the first championship in franchise history.

Casey's reputation as a defensive guru undoubtedly appeals to the Raptors after they finished 30th in the league in defensive efficiency last season, allowing 110 points per 100 possessions. The Mavericks finished seventh in the same category (102.3 points per 100 possessions) and further shed their reputation as defensive pushovers in the playoffs with successful schemes against the likes of Kobe Bryant, Kevin Durant, Russell Westbrook and, most notably, LeBron James.

Casey, 54, has been waiting for a second shot at a top job since being dismissed by the Timberwolves with a record of 20-20 during the 2006-07 season. He narrowly missed out on coaching jobs last summer with the Atlanta Hawks and Los Angeles Clippers and was a co-finalist with Frank this spring for the jobs in Houston and Golden State that went to Kevin McHale and Mark Jackson, respectively.

Frank was 225-241 in parts of seven seasons coaching the Nets before joining Doc Rivers' staff in Boston this past season, replacing Chicago Bulls coach Tom Thibodeau. He interviewed with the Detroit Pistons on Wednesday and is a finalist for that job as well along with former Hawks coach Mike Woodson and Milwaukee Bucks assistant coach Kelvin Sampson.

Marc Stein is a senior NBA writer for ESPN.com.