The former Wigan centre-back hails his team-mate who has come into Roberto Martinez's side in recent weeks and won the man-of-the-match award in the Toffees' 4-0 win over QPR
With Phil Jagielka and Sylvain Distin sidelined due to hamstring injuries, Alcaraz and Stones have stepped in at the heart of Everton's defence in the last two matches.
The 19-year-old Stones – who joined from Barnsley in January last year – was the man-of-the-match in the Merseyside club's 4-0 FA Cup win over QPR on Saturday after impressing in the Premier League draw at Stoke City.
"He is a young lad and he has a big future," Alcaraz told evertontv.
"He is a great player and I think he is going to improve a lot. He had a great game against Stoke and also now [against QPR].
"He has a lot of quality but he is a young guy and he needs more games to improve and learn.
"But if he continues in this way then he has a big future and he will make a big impact in the Premier League."
Everton travel to Stevenage in the fourth round of the FA Cup later this month and Alcaraz – who won the FA Cup with Everton manager Roberto Martinez at Wigan last season – is hopeful of another lengthy cup run.
"We knew how important it was to win and we are through to the next round," he added.
"We will do everything we can to get to the final at Wembley. It was a good memory last year and I want to repeat that again."