Mauricio Pochettino says Tottenham “cannot expect too much” from Tanguy Ndombele despite investing a club-record £65 million ($79m) in him.
Spurs spent big on the 23-year-old midfielder when luring him away from Lyon.
He has shown flashes of what he is capable of during pre-season, with there the promise of much more to come.
Pochettino is, however, aware that adapting to life in England can be “difficult” and has urged patience when it comes to Ndombele and his immediate impact in north London.
The Argentine tactician has said: "For him it’s difficult. We cannot expect too much.
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"We need to accept he needs time to adapt to first a new culture, a new country, new habits.
"Of course it’s only him who arrived to the club and that makes it more difficult. When a few players are new they can help each other but it’s only him.
"We need to give him time but I am happy in the way he is adapting. He is open to improving and learning but needs time to [until we] see the best version of him."
Pochettino has been freed to spend again this summer after two windows of no movement at Spurs.
Ndombele is among those to have been drafted in and there could be more arrivals before the Premier League deadline passes on Thursday.
Pochettino has hinted at further additions, although he has previously pointed out that recruitment calls lie outside of his control as head coach.
“I am happy with my squad,” he added .
“In every season we are always open to improve the squad and to try to find the right players to be stronger and better and there are still four days.
“We'll see what happens in the next few days.”
Spurs are reported to still have a number of targets in their sights.
Fulham left-back Ryan Sessegnon has seen a switch across London mooted for some time and has entered the final year of his contract at Craven Cottage, while Real Betis midfielder Giovanni Lo Celso has been the subject of speculation regarding a move to England for much of the summer.