The Black Cats are embroiled in a scrap to stay up and are currently bottom of the table, seven points from safety, ahead of Monday's meeting with Tottenham Hotspur.
However, Sunderland do have up to three games in hand on many of their fellow strugglers and Poyet is convinced his men can still beat the drop.
However, the Uruguayan recognises that it would be a mistake not to plan for the worst-case scenario and has made it clear that he would still be committed to the club if they suffer relegation.
"I've got a contract here and I always plan ahead. I'm unselfish like that - I plan two or three years ahead," Poyet, who signed a two-year deal when he succeeded Paolo Di Canio in October, said in the Sunday Mirror.
"It's not just about now. If I didn't plan ahead, in three years' time - if I'm still here - I will blame myself for not doing it.
"I was talking to (new sporting director) Lee Congerton. He told me a couple of things he was doing, and I was tempted to click on the plan for pre-season in the Championship and have a look.
"We've not put anything in place for that yet, but if people say you're planning for games in the Championship, you're expecting to be there.
"I'm not, but you have to have an element of realism. We need to start planning for all eventualities."
Watch Tottenham v Sunderland on Monday Night Football. Coverage begins at 7pm on Sky Sports 1.