[Tim MacMahon] Sources: Mavericks GM Nico Harrison is making major changes to the team’s health and performance group again. Among the dismissals: athletic performance director Keith Belton, Harrison’s hire last summer; and head athletic trainer Dionne Calhoun. https://www.rawchili.com/4246430/ #basketball #Dallas #DallasMavericks #Mavericks #NationalBasketballAssociation #NBA #NBAWesternConference #NBAWesternConferenceSouthwestDivision #Texas