Manchester United have a "strong and secure" centre-back partnership in Chris Smalling and Daley Blind after a solid start to the season, says Jamie Carragher.
In their five games together this month in all competitions, Louis van Gaal's side have conceded just once, despite Blind playing the majority of last season in defensive midfield.
United's start of four wins out of five is an improvement on last term's opening five competitive games, where they won only once, and Sky Sports pundit Carragher says it is a reflection of the work done behind the scenes with the pair.
"The work that has been done on the training ground with Chris Smalling and Daley Blind has helped," he said ahead of United's Super Sunday clash at Swansea.
"They've looked a very good partnership, even though there were question marks over Blind playing there. They've looked strong and secure."
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Blind played the majority of his earlier years at Ajax as a left-back, but the switch to central defence has been seamless so far this term alongside Smalling, who himself is in his sixth season as a Manchester United regular.
Despite only scoring twice in three games in the league, Carragher insists it is the results that count for Manchester United, though the trip to south Wales to face Garry Monk's Swansea will not be taken lightly.
"Some are criticising them for their performances this season despite them getting seven points out of nine. It's an excellent start really.
"Results are always more important than performances. Sooner or later people will want to see a bit more in the performances but at this moment but you can't complain about the points on the board.
"I think it will be a difficult game for United, it's a difficult place for anyone to go at Swansea now. Garry Monk has made the Liberty Stadium a tough place to go.
"Swansea are a very good team, and over the last couple of years he's changed them slightly. They are a lot harder to beat, and I think it'll be a very good game. Of course Manchester United can go there and win, but it won't be easy."
Wayne Rooney's hat-trick in midweek against Club Brugge were his first goals in 10 games for United, and as well as doing wonders for the England striker's confidence, Carragher believes the emphatic 4-0 win has given United's attack a timely boost.
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"Every player, even a player of Wayne Rooney's ability and with what he's achieved in the game, will still need a confidence boost," Carragher said.
"It will do Wayne wonders but also the team as well. They have been struggling to score goals, not just Wayne, so to get a few goals in the week, it gives them that confidence not just for this game but for the coming week.
"They seem to have been very successful at one end of the pitch, but at the other end they obviously need to start scoring more goals. I'm sure it will do them well."
Ahead of Super Sunday's other encounter, Carragher has been impressed by the way Alex Neil's Norwich have performed on their return to the top flight as they travel to Southampton for the 1.30pm kick-off.
"Norwich have started well. They were really unfortunate in the first game against Palace, and again against Stoke.
"Four points out of nine is decent, but more importantly the performances bode well for the future and the manager can be confident they can compete at this level."
With Southampton's Ronald Koeman among several top flight managers unhappy with the timing of the transfer window as the futures of Victor Wanyama and Saido Mane remain unclear, Carragher insists the problem is the same for all clubs throughout the Premier League and beyond.
"It's the same for everyone, not just for Southampton. Lots of managers have come out and said they wished the window would end before the first game but everyone is in the same boat.
"You worry about players going, and Norwich have the same situation with Lewis Grabban."