Holtby, drafted in to replace the injured Aaron Lennon, admits the draw was a blow, but still backed the team to come through.
The German said: "It was a good performance in the second half but if we want to play in the Champions League, we want to win those games.
"It's about professionalism, and playing at a big club. If you play a lot of games in your career, you get that calmness as well.
"If you look at the whole season, all the effort we have put in, I think we deserve [to qualify for the Champions League] but it's got to be done at the end."