Speaking on BT Sport on Thursday, Owen Hargreaves said: "Erik ten Hag felt he needed to make some subs obviously after the game against Brighton on Sunday, the players were tired and he felt he needed to make changes.
"I think up until about six weeks ago he probably got every sub right. At Anfield he had a couple of moments that didn't go his way, at home against Sevilla, a couple of subs that didn't go his way, and obviously today.
"That's the one thing they need to address is the depth and obviously they will try to do that in the summer transfer window."
Manchester United were leading 2–0 against Tottenham on Thursday but Spurs mounted a comeback after the break, scoring twice to rescue a point.
Ten Hag brought on Fred, Anthony Martial, Tyrell Malacia and Wout Weghorst in the second half with all four players failing to make an impact on the pitch.
