The Red Devils boss has already spent £60m on Villarreal defender Eric Bailly and Benfica centre-half Victor Lindelof since taking over the reins of the Old Trafford from Louis van Gaal in May 2016.
Bailly was a big hit in the opening months of the 2016-17 season before he suffered a serious knee problem in October 2016 to curtail his impressive start.
The Ivory Coast international has struggled to bounce back from that setback and Mourinho’s faith in the 24-year-old defender appears to have been eroded to a point where Bailly is facing a bleak future at Old Trafford.
Mourinho used Lindelof sparingly following his arrival from Benfica last summer, starting 13 games and making four substitute appearances in the 2017-18 Premier League campaign.
The Sweden international has established himself as as first-team regular in the current campaign as Mourinho appeared to settle on a partnership with Chris Smalling.
Manchester United have conceded 21 times in 12 games in the Premier League to raise serious questions about the Red Devils defence.
Former Chelsea FC defender Townsend believes that Mourinho needs defensive signings to make immediate improvements to the Manchester United back four.
“I know he [Mourinho] has spent a lot of money, and he has bought Bailly and Lindelof, [but] they aren’t good enough,” Townsend told Sky Sports’ The Debate on Tuesday night.
“He can’t get the best out of himself or Man United without a back four he can lean on. He doesn’t have it [a solid back four].”
Manchester United are in eighth place in the Premier League table following their 3-1 loss to Manchester City in the derby last Sunday.
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