Cancellara hit the deck with about 15 km to go in the race, leaving him with a bloodied arm and ruining his chances of claiming a medal.
"Looks like a hard night with a lots of pain. happy is not broken but the pain will be on! For the timetrial nothing is shure yet 50/50change (sic)," the 31-year-old said on his Twitter account.
A Swiss cycling team spokeswoman said Cancellara was bruised but had not suffered any broken bones and a decision on whether he would ride in Wednesday's time trial would be made in the coming days.
Cancellara, who was in a leading group of 32, missed a right-hand turn and crashed into the safety barriers.
He managed to get back on his bike but struggled to hold his handlebar with his right hand.
"Have no words left. The tears are stronger than the pain," Cancellara tweeted after the finish.