Jamie Carragher has praised Chris Smalling and Daley Blind for building a successful partnership in the heart of Manchester United's defence.
Despite arriving at Old Trafford as a defensive midfield, Blind has been used a centre-back alongside Smalling in the early stages of the season, and Louis van Gaal's side have conceded just once in five competitive matches.
"The work that has been done on the training ground with Chris Smalling and Daley Blind has helped," the former Liverpool defender told Sky Sports News.
"They've looked a very good partnership, even though there were question marks over Blind playing there. They've looked strong and secure."
Van Gaal's side take on Swansea City at the Liberty Stadium on Sunday.