The Spanish champions have been inconsistent in La Liga so far this season and they currently sit eight points behind their Catalan rivals, a gap Khedira believes will be tough to bridge.
"Of course, it is difficult with a team as strong as Barcelona and with the difference in points between us and them," he was quoted as saying by Marca.
"We do not have our destiny in our own hands and it is not a good feeling to have to wait for them to falter.
"But we will give it our best. If we can win our games and show some consistency in doing so then I am sure that something good will happen."Jose Mourinho's side draw 2-2 at Camp Nou on Sunday, and the former Stuttgart man has admitted that his team-mates felt they could have come away with more than a point.
"We would have liked to win. The development of the game was very positive for us, so we were upset at not being able to defeat them," he added.
With the additions of Luka Modric and Michael Essien to the Madrid ranks, Khedira has seen more time on the bench this season, despite being a regular throughout the previous campaign. However, he remains convinced that he is an important player to his coach.
"Up to now, I have been lucky. I have been chosen to play in almost all the important matches. Mourinho knows what he does and what he has in me. This is my third year at Real, and when I've been fit I've almost always played," he continued.
The 25-year-old also reflected on Los Blancos' upcoming Champions League double header against Borussia Dortmund.
"The evolution of Borussia is phenomenal. Marco Reus, Mario Gotze and Marcel Schmelzer are fantastic players. They put Manchester City up against the wall. Now they are one of the big teams, we know that," he concluded.
Khedira is currently in Dublin with the German national team as they prepare for their World Cup qualifier against Republic of Ireland on Friday.