Pochettino, who took over from Nigel Adkins midway through the season, will have the chance to stamp his mark on the Saints squad for the first time this summer.
And while Argentinian is determined to hang on to his key men, he reckons several new faces can help the club challenge higher up the table.
"I never rest," Pochettino, whose side finished 14th, told the Southern Daily Echo. "I always keep on thinking and keep on working for the next season.
"I think the first goal was achieved and that was actually to stay in the league and we are going to be playing in the Premier League next season.
"We want to maintain the core of our players and our squad.
"Next year they will perform a lot better and be a lot more settled because they've already had that one year under their belts.
"The players that do join us hopefully will add more quality and strength to us as well."
Pochettino had threatened to quit if Nicola Cortese left the club but is ready to talk about summer signings now the executive chairman is staying put.
"It is something I will speak about with Nicola," Pochettino added.
"It's a great piece of news. It's the best possible news that Nicola Cortese is going to be with us next season and is very good for the squad and the club in general."