Goals from Billy Clarke, Jordy Hiwula and Timothee Dieng helped to secure a share of the spoils for McCall's men after a breathless Yorkshire derby at the Northern Commercials Stadium.
City could have snatched a winner late on but Hiwula hit the bar with a rising drive from inside the area with only five minutes of normal time left.
McCall said: "It was an outstanding game played out in a fantastic atmosphere.
"What a great advert for this division. Two proper football clubs going head to head.
"They (Sheffield United) are a really good side playing with a lot of momentum and belief at the moment.
"As I said before the game, they have a lot of good players within their squad and plenty of experience.
"In Billy Sharp, they also have a fantastic striker full of confidence. Our defenders probably won't come up against better in the league this season the form he is in at present.
"To go toe-to-toe with them then, I am really proud of the players.
"Their eleven today (Saturday) could be the strongest we face in the league all season so it is very encouraging to see us match them.
"They had opportunities and looked dangerous in patches but so did we.
"The only disappointing thing from our point of view is the second and third goals we conceded.
"We spoke to the lads yesterday (Friday) and showed them on the video that they take quick free-kicks. We reiterated that again at half time yet we get done from one early in the second half.
"For the third goal, it is a poor corner really so it is frustrating to see it still make its way through and get bundled in.
"Looking at the game as a whole though, I'm as pleased as I can be with a point at home."
McCall made four changes to his side for the visit of the Blades to the Northern Commercials Stadium.
Goalscorers Dieng Hiwula, Clarke, plus James Hanson, were all recalled while Rory McArdle moved across to right back and Romain Vincelot returned to centre half.
For the first time this season, McCall also chose not to make any substitutions during the game.
McCall added: "They (Sheffield United) have a fantastic player in (Mark) Duffy who plays just behind the strikers and causes problems but I thought Tim Dieng did a great job on him.
"Billy (Clarke) was a livewire and Jordy (Hiwula) gave them problems. James (Hanson) needs the games to get himself back to top fitness but it was still a great shift from him to get 90 minutes in.
"In terms of playing Rory (McArdle) at right back, they have had a lot of joy playing deep balls to their left wing-back in recent games. He's a tall lad but I felt Rory dealt with everything there.
"It was maybe a bit harsh to leave Darbs (Stephen Darby) out but Rory gave us that little bit more presence aerially.
"Probably for the first time in my managerial career, I didn't make a substitution.
"You look at Hans (James Hanson), maybe you think he could be tiring having just come back (from injury) but then you have to also think who will give you that physical presence in attack and in defence when we're defending set-pieces.
"We didn't want to get done in the last five minutes or so from a corner or a free-kick.
"You think maybe Billy is tiring but then next minute he'll pop up in a hole and create something.
"We could have brought someone on to replace Jordy but then he goes on a run and gets away from their defender and gets hauled down for a booking.
"I'd said to the subs after the game that I apologise for not being able to get them on in such a fantastic game but, for me, the shape, the team and the system did terrific today."