10:02am: The Hawks have officially signed Mack to a 10-day contract, the team announced in a press release.
Mack, 23, has made several NBA and D-League stops this season, including multiple stints with the Wizards, and a pair of 10-day contracts with the Sixers. Mack has also appeared in 23 games with the D-League's Maine Red Claws, averaging 20.1 PPG and 7.7 APG with the club. In limited action in 11 games for Washington and Philadelphia, the young point guard averaged 3.5 PPG and 2.2 APG.
It's not yet clear whether Mack will receive a 10-day contract or a rest-of-season deal from the Hawks. Given the team's cap flexibility, it wouldn't be a surprise to see Atlanta sign Mack to a contract that includes a non-guaranteed minimum salary for next season, giving the club the option of taking an extended look at him in summer-league action and in camp.