Toby Alderweireld, Danny Rose and Mousa Dembele were all expected to leave this summer, and they still could if they are willing to move overseas.
The Argentine added: "We have a very good squad, we have very good players and it is not easy to add players that improve that".
Pochettino added: "What the club is doing is showing it is so courageous".
"Of course it's hard to understand for people in football that Tottenham didn't sign or sell players, but sometimes in football you need to behave differently", he said.More news: Pompeo vows to enforce sanctions on Iran
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If we are happy with our squad and can not improve our squad, sometimes it's better to keep our squad together.
Grealish, whose future has been the subject of intense speculation for the whole summer, trained at Villa's Bodymoor Heath training ground on Thursday morning and club insiders are now confident he won't be sold before the 5pm transfer deadline.
He said: "These players were never away from our thoughts". He played a key part in Bruce's side as they finished fourth, before losing to Fulham in the play-off final. Aston Villa have been strongly linked with a loan move that would see the Scotsman rejoin on loan, but talks seem to have broken down over the past few weeks, with new Hammers manager Manuel Pellegrini deciding he wants to keep Snodgrass until he has decided whether he will get game time or not. I am so proud of them because they were very focused on trying to arrive in a very good condition. And then with Brexit it is worse because the cost is 30 per cent more. "Drama is many things in life but football is joy".