Chelsea boss Andre Villas-Boas insists he can be flexible.
"I think we have played various systems," he said ahead of Saturday's trip to Blackburn.
"We tried a 4-1-3-2 against West Brom, then played the Norwich game with that structure.
"We had a different one in the second half against Manchester United, 4-2-3-1, with (Juan) Mata in the number 10, and we've tried the diamond formation.
"But it's not about a structure that will make us defend or attack better."