Chelsea hired the 51-year-old former Tottenham Hotspur and Paris St Germain boss in May after finishing 12th in the Premier League following a tumultuous campaign, which saw Thomas Tuchel, Graham Potter and Frank Lampard take charge at Stamford Bridge.
"Different players arrived in different circumstances but of course now is an opportunity," Pochettino told Chelsea's website, outlining his plans for the team ahead of the pre-season.
Chelsea begin their preparations for the new campaign in the United States with a game against National League champions Wrexham on July 19th.
"I hope we can help them to achieve their best level, a higher level, and try to perform for Chelsea in the way that people expect," he said.
"Now is a new start, a fresh start, and I think they need to show their real quality. But we need to create this platform for them to feel comfortable and breathing space for them to perform and improve."
Pochettino said former Benfica midfielder Fernandez, who was named the best youngster at last year's World Cup after helping Argentina clinch the title, needed rest after a gruelling schedule.
"The Premier League is a really tough competition and he changes everything – culture, language, everything – and it is always difficult to adapt," Pochettino said.
Pochettino added that Mudryk's "mindset and everything is different" than Fernandez's, which is why he intends to spend more time with the Ukrainian winger.
Sterling is one of the more experienced players in the squad but is yet to replicate the performances that made him a crucial part of Manchester City, with whom he won 10 major trophies, having scored just nine goals in 38 appearances for Chelsea.
"It's not always to blame the player... We need to see us and see what is going on and why they are not performing in the way that we expect and then, of course, when all is clear, we cannot give excuses to them to not perform." Pochettino added.
