Ullao grew up in the Dallas area and joined the club through the homegrown program in 2010. The 22-year-old made his MLS debut with one game in 2011 but hasn’t played since then. He’s spent the past three seasons with the FC Dallas Reserves club.
Hassli came to FC Dallas in a trade with Toronto FC last year. The former MLS All-Star made 15 appearances for FC Dallas last season before a back injury sidelined the Frenchman. The back injury resurfaced in the preseason this year.
The moves Friday came a day before the FC Dallas season opener at home against Montreal.