Manchester United's defence has improved considerably since Ole Gunnar Solskjaer replaced Jose Mourinho as manager last month.
Under Mourinho the Red Devils conceded 29 goals in 17 Premier League games. Even the great David de Gea was making mistakes in goal.
But with Solskjaer in charge, United have won five out of five league games and shipped only three goals.
Focusing on Sunday's 1-0 win against Tottenham, Solskjaer went with a centre-back partnership of Victor Lindelof and Phil Jones at Wembley and they were superb.
Lindelof was particularly fantastic and made a number of crunching tackles that were reminiscent of Nemanja Vidic, such as his last-ditch challenge on Harry Winks.
However, as impressive as United's defence has been recently, the fact remains they lack a world-class centre-back.
Napoli's Kalidou Koulibaly, for example, fits into that category and is reportedly a top target for the summer because a deal in January isn't possible.
Koulibaly would represent an upgrade on each and every one of United's five centre-backs and according to the Telegraph, Solskjaer has come to a decision on his current options.
Starting with Lindelof, Solskjaer views the 24-year-old as United's first-choice centre-back and wants to find him a "reliable, high-quality" partner.
Chris Smalling only signed an extension with United last month that keeps him at the club until June 2020, so he isn't going anywhere.
As for Jones, the Englishman's contract expires in the summer and United have an option to extend his stay by 12 months, but Solskjaer is concerned about his injury problems.
Eric Bailly's struggle to stay fit has also become a problem for Solskjaer, but he's one of United's best defenders and also contracted until June 2020.
And then there's Marcos Rojo, who has barely featured for United this season due to injuries and is seen by Solskjaer as his most expendable centre-back. He will be sold in the summer.
Rojo returned home to Argentina midway through United's Dubai training camp last week, which Solskjaer explained in a recent press conference.
"He has gone back to Argentina for a while because of his injury," said the Norwegian. "How long will he be out for? How long is a piece of rope.
"For him it was mentally important to go away and come back fresh again."