The Toon will host United at St James' Park as they chase a top four finish and Champions League qualification. Tindall stepped in for Eddie Howe to preview the game, with the Magpies manager ill.
Tindall explained, "He's been really poorly the last couple of days in bed. We've been in daily contact. We've been speaking three or four times a day so it's not affected any of the preparations. We've still got a couple of days and I'm sure he'll be fine for the weekend."
Newcastle sit fifth on the Premier League table on goal difference behind fourth place Chelsea.
Tindall continued: "With eight games to go, there are a lot of teams fighting for the same as what we are. All we can control is our own performances and what we do, the most important thing is that we approach every game as we have done all season and give the best account of ourselves.
"Hopefully that will be enough to achieve our end goal.
"We're in a position that we would have wanted to be in with eight games remaining. There are a lot of teams fighting for those positions. We've got a busy week coming up but the most important thing is the Man Utd game and making sure we prepare right for that.
"If we can deliver a performance and get the result we want it takes us one step closer to where we want to get to."
Gordon facing fitness test
Tindall admits management hope Anthony Gordon will make Sunday's game. Gordon has been recovering from a knock for the past fortnight.
"He's had a decent week with the physios. He was back out on grass for a pitch session yesterday so we'll assess him again today to see how he's responded to that session then we'll have to make a late call on whether he's available for the bench on Sunday."
On facing United, Tindall says there'll be no underestimating the fallen giants, which remain in the bottom half of the table.
Tindall is confident Toon fans will turn up the heat on the visitors on Sunday.
He said, "It's another important game for us. No matter who Man United come up against, it's a big game. A huge football club with big expectations. We will prepare the same for Man United as how we did against Leicester. The lads know how important the game is with only eight games remaining.
"We know the importance of every result. Hopefully it's going to be a good game at St James' Park and we deliver the performance we know we can to win the game.
"There's always been that rivalry there between Newcastle and Man United. They're the type of games as a player, coach and manager that you want to be involved in. We know it's going to be a fantastic atmosphere. It always is when you play Man United - and it's down to us to go and deliver a performance that wins us the game. They're a good side.
"They have only lost one of their last six so they're certainly a different side to the one we faced at Old Trafford. We know we need to be at our best."
"We're on a great journey"
Winning the Carabao Cup and earning another Champions League campaign would crown an exceptional season for Newcastle. Tindall says everyone inside the club is determined to maintain their momentum and are hungry for more glory.
He said, "It's certainly been a great journey for us and one that we wouldn't have expected certainly so soon. There have been some incredible moments and achievements along the journey and I've been absolutely delighted.
"We knew what the football club meant to the city arriving here. We knew the football club hadn't won a trophy for so long and the importance of trying to achieve that. We spoke when we arrived about how we wanted to achieve that and deliver that, and we wanted to be able to help the football club win their first trophy in such a long time.
"For us, it doesn't stop there. The most important thing for us is now is Manchester United and focusing on that, and making sure we deliver the performances week in, week out and get that consistency that will hopefully lead to more success."