The Celtics picked Duke forward Jayson Tatum with the third pick in the NBA Draft Thursday. With a loaded backcourt that features All-Star Isaiah Thomas, defensive star Avery Bradley, and Marcus Smart, the choice fills a need in the frontcourt for the Celtics, who reached the Eastern Conference Finals this season but were overwhelmed by the star-studded Cavaliers. “It’s an incredible feeling. I’ve got to give honor to god to be in this position. It’s everything I wished for and more,” Tatum said in a television interview after he was chosen. “I’m trying not to cry right now.” The Celtics originally held the top pick in Thursday’s draft, but traded down to No. 3. The 76ers took guard Markelle Fultz with the first pick and the Lakers chose guard Lonzo Ball with the second. The Celtics also have three picks in the second round, at Nos. 37, 53, and 56.