Valencia is convinced United will win their 20th title. But he cannot stand the thought of Tevez spoiling the party.
He told The Sun: "If Carlos plays against us, I'm sure he'll be motivated. He's an excellent player, able to change a match in an instant. What he did against Chelsea was no surprise.
"But for Tevez to score the winner? I hope it doesn't happen.
"And for us to fail and lose the title will bring pain for months. But I'm confident in my team."