Celtics

Celtics

The Celtics open play at Vegas Summer League on Saturday against the Al Horford-poaching Philadelphia Sixers (5 p.m., NBC Sports Boston). There are only two players from last season's NBA roster — Robert Williams and Guerschon Yabusele — but no shortage of intrigue with all four of the team’s recent draft picks out west (though it doesn’t seem likely that top overall selection, Romeo Langford will play as he recovers from thumb surgery).