The Australian midfielder managed to get through 27 minutes of the Red Bulls' 2-1 win over Philadelphia Union last week as he continues to improve from a hamstring injury that saw him sidelined for two league matches.
Ahead of the Red Bull Arena meeting with the Dynamo, Petke is still not sold on Cahill's fitness which has prompted him to tread carefully with the former Everton star.
"Tim needs to feel 100 percent before we come back [with him as a starter], for his sake and for our sake," Petke told reporters after Monday's training session. "It's important that we get him back.
"Having said that, we'll figure it out tomorrow and do what's best for him and the team. He did get some minutes vs. Philly, but if he's not feeling 100 percent then we need to protect him and protect us as well."
The Red Bulls currently sit eighth on the Western Conference table with seven points from seven outings following their season-first win over the Union in midweek.
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