There's no knocking Sastre's consistency in the Tour de France but the 33-year-old Spaniard has yet to really show he's got what it takes to win the race.
No one in this year's field can match his record - since his debut in 2001 when he finished 20th, he's finished every Tour and made the top ten every year except 2005.
Last season saw him just miss out in a podium slot in fourth but the downside is that he's managed just one stage success (back in 2003) and only four in his career as a whole.
However there were signs of a more positive gameplan as he finished second to Denis Menchov in the 2007 Tour of Spain and since then everything has been geared towards three main targets this season - the Tour de France, the Vuelta and the Olympics.
That's meant he's been pretty quiet in the early part of the season, bypassing the Giro d'Italia and barely showing up in the early-season Classics.
Climbing is undoubtedly his forte and the reduction in the time trials this year is a major boost because that's been the area where he's lost ground to most of his rivals.
However it's got to be a worry that he could only manage a subdued 20th-placed finish in the Dauphine Libere in June because that's hardly the sort of form which suggests he ready to make the step up into major Tour contender especially as his subdued form in the first week or so of the Tour last year ultimately cost him dear.
It will also be fascinating to see the dynamics within the CSC team.
Sastre goes into the Tour as the team leader but with brothers Andy and Frank Schleck also seen as contenders by many, that pecking order could easily come under pressure midway through the race.
