Although the Finn secured his best qualifying result since his return to Maranello with third, Raikkonen was then unable to challenge Lewis Hamilton and Nico Rosberg during the race.
The 2007 world champion even dropped out of podium contention after a bizarre spin caused by engine maps pushed him back behind Williams’ Valtteri Bottas. With team-mate Sebastian Vettel recovering through the field to claim P5, Ferrari failed to place one of its drivers in the top three for the first time in 2015.
“We have to improve in all the areas,” Räikkönen said.
“The car is actually pretty nice, but we had to fuel save quite a bit and that's a limiting factor. It's all of those things, it's not just one.
“It was not the nicest weekend for us but we still came out with fourth and fifth place. It's not a disaster but of course we are aiming for better results and it feels disappointing to finish where we finished.”
Despite the Montreal setbacks, Raikkonen remains upbeat about Ferrari’s prospects, especially after a dismal 2014 campaign that saw the Italian squad only clinch a couple of podium finishes.
“We have come a very long way since last year, but as we see we still have a long way to go."
“I'm sure [Circuit Gilles Villeneuve] is one of the most difficult for us, but we've done our best and we will keep working hard to improve the areas”
“We need to keep working in the same way and I'm sure we'll get there, but we need more time.”
Click here for the best quotes from last weekend's Canadian Grand Prix