Service ace: Djokovic back with rebuilt serve at Aussie Open

Serbia's Novak Djokovic gestures during a press conference at the Australian Open tennis championships in Melbourne, Australia, Saturday, Jan. 13, 2018. (AP Photo/Vincent Thian)

MELBOURNE, Australia — Novak Djokovic is back from six months off the tour with a remodeled service motion partly inspired by Andre Agassi and a growing confidence he can get his sore right elbow through the Australian Open.