Manchester United head coach Erik ten Hag has said that the Red Devils have made an "unimaginable" amount of "average" signings over the last few years.
The 20-time English champions have largely struggled since Sir Alex Ferguson's departure as head coach in 2013, while they finished sixth in the Premier League table last term, 13 points behind fourth-placed Tottenham Hotspur.
Man United are currently fourth in this season's Premier League, level on points with third-placed Newcastle United, while they are still active in the Europa League, FA Cup and EFL Cup.
Ten Hag has said that poor signings have contributed to the team's failures in recent years, and the Dutchman was keen to bring in players with "personalities" in his first window at the helm.
Tyrell Malacia, Christian Eriksen, Lisandro Martinez, Casemiro and Antony arrived at the club over the summer, and all five have played important roles for the team this term.
"Manchester United didn't exactly have the fear factor last season," Ten Hag told Voetbal International.
"I looked at the culture of the club. I asked "How did Manchester United become great?" The club has bought an unimaginable number of players in recent years who have not been good enough.
"Most purchases have been average - and at United average is not good enough. United's shirt weighs heavily. Only real personalities, who can perform under great pressure, can play here.
"We needed personalities. That's why the acquisition of Casemiro was so important. Along with Raphael Varane, we now have a second player who has experience of winning titles.
"Malacia, Martinez, Casemiro, Antony are all fighters, while Christian Eriksen is a technical winner and a great personality. We want the best of the best. Any players we bring to Manchester United must meet the highest standard."
Man United progressed to the fourth round of the FA Cup courtesy of a 3-1 victory over fellow Premier League side Everton at Old Trafford on Friday night.
The Red Devils will now welcome Charlton Athletic in the quarter-finals of the EFL Cup on Tuesday before hosting Manchester City in the Premier League next weekend.
Ten Hag's side will be in Europa League action next month, meanwhile, as they prepare to take on Barcelona in a knockout round playoff.
