Brad Guzan had three saves for Atlanta in United's 0-0 tie with Inter Miami on Wednesday night.
It was Guzan's second shutout — both against expansion teams — in three games. He had five saves in a 2-0 win over Nashville on Aug. 22.
Atlanta (3-4-1) has just one win — and four losses — in its last six games.
Miami (1-6-1) has been shut out four times and has only one multi-goal game, its 3-2 win over Orlando City on Aug. 22, this season.
Atlanta had 60.5% possession. but Inter Miami had a 10-5 advantage in total shots, including 3-1 in shots on target.