Blackwell had to settle for a goalless draw in his first match in charge of the club after being handed the reins late on Thursday in the wake of former manager Bryan Robson's departure.

United had the chances to clinch a first-half lead in their fifth-round clash with Middlesbrough at Bramall Lane, with striker Kevin Beattie striking the post with a free-kick late on.

However, the visitors could themselves have snatched it in the second half as they carved out four clear chances in as many minutes around the hour mark, before Emanuel Pogatetz saw a late header blocked.

But neither side were able to make a decisive breakthrough, meaning they face a replay at the Riverside on February 26.

After beating Bolton - at the Reebok Stadium in the third round - and Manchester City already this season, Blackwell sees no reason why his side cannot make it a hat-trick later this month.

"It's not a bad start to my reign against a Middlesbrough side in a rich vein of form at the moment," said Blackwell, still to sign a contract on his short-term deal to the end of the season.

"We were unlucky with some of our set plays, particularly the one just before half-time, but I was pleased with the attitude shown.

"Without a doubt I feel we can win the replay - I believe we can win every game.

"I said to the players afterwards 'tell me what you want' because sometimes it's the manager who gets the stick.

"But there are times when you have to ask the players what they want out of their career, where they want to go and where they want to take this football club.

"They want to go up, and if that's the case then let's start doing something about it."

Blackwell revealed the comical-looking collision between Beattie and Michael Tonge which led to the former's free-kick hitting the post was not amateur dramatics, but a planned ploy.

It was the nearest either side came to scoring, with Blackwell adding: "I said to the lads I wanted them to be different.

"That free-kick was something I'd used the last time I was here.

"A lot of the Sheffield United fans will have immediately realised where it came from because on that occasion Michael Brown hit the bar in a quarter-final against Leeds.

"So I decided to use it again, and it was something significant to the fans, and sure enough many of them recognised it straightaway.

"The Boro fans didn't. They thought it was a right cock-up, but that is what we wanted, to make them think that and ensure Mark Schwarzer and their wall relaxed for a second.

"We almost caught them on the hop, and it was unfortunate it came off (Stewart) Downing's ankle and that pushed it on to the post and away.

"It would have been a great time to score - just before half-time."

Blackwell, assistant to former Blades boss Neil Warnock for several seasons prior to leaving in 2004 to manage Leeds, was of the same mind as Gareth Southgate that a draw was a fair result.

Boro's purple patch saw Paddy Kenny make tip-over saves from Mido and David Wheater, Stewart Downing struck a volley inches wide, while Fabio Rochemback dragged a first-time shot past the post.

Southgate said: "We knew this would be a tough game with a new manager coming in and a great chance for them to cause an upset, so they had plenty of motivation.

"But in the end we're still in there fighting which is the most important thing, although we can't afford to look beyond the replay.

"Obviously, it's getting to the stage where it gets exciting, and there's a great spirit amongst the players. They want to do well and to win it.

"But as a team we're at our best when we focus on the next challenge, otherwise we get a bit carried away with ourselves."