The Mexican says they will need an aggressive strategy for the race.
24th May, 2014 (F1 Plus / Rosie Baillie) - Sergio Perez may have qualified 10th, but he feels there was more speed in the car.
"Although it's good to be in the top ten, I'm feeling a bit disappointed not to be higher up the grid." Perez said.
"My hot lap in Q3 was quite difficult and I had a lock-up going into the Nouvelle Chicane - so there was definitely more speed in the car."
Perez felt the team didn't get the tyres to work perfectly and said an aggressive strategy is necessary for the race.
"One of the main challenges was getting the tyres in the perfect working condition and I don't think we maximised that today." he said.
"We need to look at ways to make up positions tomorrow and we should be aggressive with our strategy because I don't think there will be too many overtaking opportunities."
Teammate Nico Hulkenberg qualified just behind Perez in 11th place.
The German driver was happy with where he qualified and praised the teams traffic management.
"A place in Q3 was very close today - less than a tenth away - but I'm not feeling too disappointed because I was pretty happy with my lap in Q2." Hulkenberg said.
"There was just a tiny bit missing because it's very hard to get a perfect lap in Monaco. The traffic management by the team was good and although I had some traffic in both Q1 and Q2, it was not at the crucial moments."