Sure?
http://cqranking.com/men/asp/gen/race.asp?raceid=16976
1. BOOM Lars RAB 10'56" 40
2. VOIGT Jens SAX 03" 25
3. LEIPHEIMER Levi RSH 06" 15
4. CONTADOR VELASCO Alberto AST 06" 10
5. SAGAN Peter LIQ 10" 5
6. TONDO VOLPINI Xavier CTT 10" 3
7. MILLAR David GRM 11" 2
8. SANCHEZ GIL Luis Leon GCE 12" 1
9. KREUZIGER Roman LIQ 13" 0
10. SANCHEZ GONZALEZ Samuel EUS 15" 0
http://cqranking.com/men/asp/gen/race.asp?raceid=17267
1. PINOTTI Marco THR 05'17" 40
2. SAGAN Peter LIQ 01" 25
3. ROY Jérémy FDJ 04" 15
4. ROGERS Michael THR 04" 10
5. FLENS Rick RAB 05" 5
6. MOREAU Christophe GCE 06" 3
7. HENDERSON Gregory SKY 06" 2
8. KREUZIGER Roman LIQ 07" 1
9. PLAZA MOLINA Ruben GCE 07" 0
10. ZUBELDIA AGIRRE Haimar RSH 07" 0
http://cqranking.com/men/asp/gen/race.asp?raceid=17664
1. CANCELLARA Fabian SAX 10'21" 40
2. KREUZIGER Roman LIQ 01" 25
3. MARTIN Tony THR 03" 15
4. SAGAN Peter LIQ 03" 10
5. DEVENYNS Dries QST 10" 5
6. LARSSON Gustav Erik SAX 11" 3
7. LÖFKVIST Thomas SKY 12" 2
8. QUINZIATO Manuel LIQ 13" 1
9. GERRANS Simon SKY 13" 0
10. FUGLSANG Jakob SAX 13" 0
http://cqranking.com/men/asp/gen/race.asp?raceid=20558
1. CANCELLARA Fabian LEO 09'41" 40
2. VAN GARDEREN Tejay THR 09" 25
3. SAGAN Peter LIQ 17" 15
4. LARSSON Gustav Erik SBS 17" 10
5. KLÖDEN Andreas RSH 18" 5
6. DANIELSON Tom GRM 20" 3
7. VELITS Peter THR 21" 2
8. MOLLEMA Bauke RAB 22" 1
9. LEIPHEIMER Levi RSH 22" 0
10. GERDEMANN Linus LEO 22" 0
I have no idea why you are so certain Sagan 'won't come close to top 10 in the TDF prologue'. Considering these results