Nuno Espirito Santo's side host West Ham on Monday sitting 11 points clear of the drop zone before Sunday's games.
They face struggling Fulham and Sheffield United immediately after playing the Hammers.
Wolves have won just three of their last 16 Premier League games and Dendoncker remains cautious about survival.
The midfielder said: "Until we're mathematically safe, then we're not safe.
"We just have to make sure we win the upcoming games; we play Fulham next week and Sheffield the week after. We're playing West Ham of course next, which we have to try and win as well.
"But we have to try and win the upcoming games until we're safe and only then can we say we're really safe.
"We have to try and finish off well. It's not really been a consistent season for us. We've had highs and lows, we've had a lot of injuries as well.
"In the last two seasons we didn't have any, or really few, but now we've had a lot this season, and to some big players as well, Raul (Jimenez) just to name one. It's a huge difference.
"He was our best goalscorer for last season and the season before, so when you don't have your best scorer, then you know it's going to be difficult.
"But that cannot be the only excuse or the only reason, so it's a mix of being unlucky at some points and having injuries."
Jimenez has returned to training with the squad after fracturing his skull in November but his workload remains restricted as the club handles his comeback with care.
"He's been training for a while now, but he still can't do headers and needs to be pretty cautious when it comes to the ball being in the air," Belgium international Dendoncker told the club's official site.
"It will be step-by-step for him and then we'll have to see when the best moment will be for him to play a game and compete again.
"But the most important thing is that he's all good now, he's better and we all just hope that he will play soon for us."