Manchester United ended the transfer window with Daniel James, Aaron Wan-Bissaka and Harry Maguire as their new signings, with fees totalling above the £140 million mark.
The Red Devils also had Romelu Lukaku leave the club on deadline day for in a £73 million deal that saw the Belgian join Inter Milan.
But former United striker Louis Saha believes the club missed a trick with not signing Tottenham's Toby Alderweireld.
Speaking to Bwin, Saha commented on the lack of approach and was left confused.
"Why United didn't trigger Alderweireld's release clause is a complete mystery to me," the ex-striker said.
"He's been excellent for Tottenham and would have instantly strengthened United's defence."
United have been linked with Alderweireld for a few windows now, and when his £25 million release clause became active it was expected they would make a move.