Colosimo missed the weekend’s 1-1 draw with Perth Glory because of a calf injury but is set to come straight back into the matchday squad at AAMI Park tonight for the meeting with fourth-placed United.
“Simon's back," coach John van't Schip said. "He had a full session (Monday) and went very well, so he will be back. He's been out quite a long period, so we have to see if he can play 90 minutes.
"That's another thing we have to look at."
The Heart need all three points in both matches, particularly the derby, as the Victory sit just two points above them in fifth position.