Although Contador has already crashed twice, the Spaniard was somewhat lucky to escape with just a bruised right knee, given that several other riders had to drop out with more serious injuries. They include Kazakh star Alexandre Vinokourov (broken thighbone) and Britain's Bradley Wiggins (broken collarbone).
Schleck, the Tour runner-up to Contador the past two years, is grateful to have enjoyed more luck than his rivals in avoiding injury.
Contador crashed early in Sunday's ninth stage - in which Vinokourov was later hurt - and banged the same knee he hurt falling in Stage 5.
Vinokourov's Astana team said on Monday he had surgery for his injury on Sunday night in Paris.
"It's sad to see to what degree luck has influenced the course of the race," Schleck said Monday. "You can avoid crashes to a certain extent, by staying at the front of the bunch and being very aware of possible dangers."
But no race strategy could account for the fact a Tour car knocked Spanish rider Juan Antonio Flecha into Dutchman Johnny Hoogerland on Sunday.
With Contador's sore knee still bothering him, Schleck will gauge the three-time champion's true fitness in the Pyrenees climbs starting Thursday. Schleck is in the driver's seat as Contador needs to make up time, a role reversal from last year when Contador beat Schleck by 39 seconds to win his third Tour.
Contador lost valuable time on the first day this year, when he was stuck behind a crash that split the peloton while Schleck stayed ahead of it.
Like the toss of a coin, Schleck got the good call that day. He is 1 minute, 30 seconds ahead of Contador in the overall standings, and 11 seconds behind two-time Tour runner-up Cadel Evans, of Australia, the other main contender.
After Monday's rest day, there are two flat stages for sprinters before riders enter the Pyrenees in Stage 12, with its colossal climb up Col du Tourmalet - one of the Tour's most famed and feared ascents.
That stage is so demanding it could decimate the field.
Frenchman Thomas Voeckler leads the race after taking the yellow jersey from Thor Hushovd, while Spaniard Luis Leon Sanchez, who won Stage 9, is second overall. But neither is a Tour contender and both should soon wilt.
Thursday's stage from Cugnaux to Luz-Ardiden lasts 131.1 miles and ends with a mammoth climb up Luz-Ardiden.