Melo is still trying to find his place in the NBA after being selected in the first round of the 2012 NBA Draft by the Boston Celtics. The Memphis Grizzlies waived him in August after he came to them via trade from the Celtics in exchange for Donte Green. The big man out of Syracuse has yet to impress any team he's been with, but the Mavs are hopeful that can change and will likely give him time to develop in the D-League, where he averaged 9.8 points, six rebounds and 3.1 blocks last season.
Dallas has mostly guaranteed contracts on their roster, so the move is a de facto training camp invite for all three players.
Kennedy, a 6'6 swingman, joined the Erie BayHawks of the D-League out of St. John's University in 2011 and has logged minutes for the Cleveland Cavaliers as recently as 2011-12, where he debuted with 12 points. McConnell previously played in Italy, where he averaged 13.6 points, 3.5 rebounds and 2.7 assists for Tezenis VE last season.