The Black Cats lie 15th after a disappointing start to their Premier League campaign, with their recent win over fellow relegation strugglers Reading only their third in 16 league games this term.
|40/1||Sunderland are 40/1 with Paddy Power to beat Manchester United 1-0 on Saturday
"To be honest, the talk of the manager had no influence on the dressing room," Cuellar told the Sunderland Echo.
"All the time, from the manager through to the chairman, they've showed their confidence in the team."
Sunderland travel to Old Trafford on Saturday, a team they have not beaten in their previous 18 attempts and haven't scored against in their past five meetings.