Despite the red card, Adu's performance had Union fans singing his name as he was ejected from the field.
"I felt good, my body felt great and my teammates were finding me in the right spots," Adu told mlssoccer.com.
"For me, when I get a reception like that from the fans, I really feed off that. When they see the effort and applaud you for it, it makes you want to go out there and give that kind of effort week in and week out. And that's exactly what I'll look to do.
"Even though we lost today, this can be a pretty good turning point for our season."