It took Ndombele just one minute and four touches to show why Tottenham splashed out around £54 million pounds (US$66 million) - a club record - to sign the France midfielder from Lyon.
Last week, United agreed a potential swap deal with Juve with Romelu Lukaku moving in the opposite direction but the Argentine reportedly priced himself out of the move with what the club deemed as "excessive" wage demands.
The England U21 worldwide is seen as one of the most highly-rated youngsters in British football and the fact he can play at left-back or further forward down the left flank will appeal to Pochettino.
The Belgium global has been one of Spurs' most important players since joining from Ajax in 2012, helping them reach a first-ever Champions League final last season.
It will come as a big blow to the playmaker, who was beset by hamstring problems last season and Pochettino admits it is a concern. You can see today a lot of younger players.
"I am happy with my squad".
With Liverpool not making any new additions to their first-team, Spurs could certainly challenge for a top-two spot and perhaps even the league title. Moreover, cash infusion they gained from reaching last season's Champions League final. I feel very good physically so I am not sure what is going to happen this year.