The phrase "wrong foot" means to start or approach something in a way that is not correct or ideal. It is often used to describe a situation where someone is beginning on the wrong path or making a mistake. Full definition
Remember when Obama was wrong footed by the question of when life begins? (firstthings.com)
17 Mamadou Sakho — 6 Made a few mistimed lunges coming into the tackle, and was wrong footed for the first Swansea goal. (kopleft.com)
Seeing Walcott enter a situation where he is being fought for the ball by Vidić makes you think he'll lose the ball, but with a quick flick of the right analog stick to push back or wrong foot from Vidić sees Walcott being able to run into free space. (thesixthaxis.com)