The south-coast club have made a fine start to the Premier League season and find themselves flying high in fifth place.
Pochettino's charges beat Fulham 2-0 last Sunday to make it seven top-flight games without defeat.
But the Argentine manager knows they will have to roll up their sleeves when they face Mark Hughes' side at the Britannia Stadium on Saturday.
He said: "It’s clear that when you win you get a good atmosphere within the team and the club which is a very good thing, but we need to stay grounded and keep on training hard and looking ahead to the next game.
"We expect a very tough and physical game (at Stoke). It’s going to be very difficult and tough.
"On average they have the tallest team in the league, so I think they still have some aspects from when Tony Pulis was manager, but there some new aspects that Mark Hughes has introduced to the team and I think that it’s a team which over 90 minutes is able to do two different styles.
"They can go for the long ball but also the short one so, overall, we expect a very tough encounter."
Southampton will monitor the fitness of midfielder Steven Davis (knee) and strikers Dani Osvaldo (knock) and Guly do Prado (knee) ahead of the game.
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