Boston Celtics sign Luke Kornet

The Boston Celtics have signed center Luke Kornet. Kornet, 26, returns to Boston after being acquired by the team as part of a three-team deal with Chicago and Washington on March 25. He played in 18 games (two starts) with the Celtics last season, averaging 4.4 points on 47.3% shooting, 2.9 rebounds, 1.1 assists, and …