There was, though, an air of what might have been in the Rangers dressing room at Hampden after they worked their way back into the semi-final.
“I think this is tough because we had the feeling we could beat them, even with 10 men,” Rohl said.
“We put a lot of effort in, showed a lot of resilience and a lot of good spirit in the second half, nice football, we were brave.
“We went to a more offensive shape and we had our moments. We were not just sitting back and I thought the equaliser was deserved.
“Then you go into extra time and then go down 2-1, but even then we had two opportunities when we were one against one.”
Rohl has been in charge of four games since succeeding Russell Martin, with two league wins book-ended by losses to Brann in the Europa League and now Celtic.
However, the German sees positive signs.
“Our reaction after the red card was outstanding,” he said. “But it is a long time, 55 minutes and then extra time, with 10 men and my team put a lot into it.
“We have to take the positives and look for improvements. I am convinced, if we continue in this direction, we will have a lot of wins this season.”