Carroll spent last season on loan at Queens Park Rangers, where familiar boss Harry Redknapp helped the 22-year-old work on his game.
The Watford-born midfielder could thrive under Pochettino, who helped a number of young English players develop into Premier League stars at Southampton.
Holtby was loaned out to Fulham for the second half of last season and, although he suffered relegation with the Cottagers, he impressed during a sustained run in the first team, scoring one goal and providing three assists in 13 league appearances.
The 23-year-old German international is a very similar type of player to Adam Lallana, so Pochettino may well be able to get the best out of him.
Another player who is back at White Hart Lane following a loan spell is Cameroon defender Beniot Assou-Ekotto.
Although the 30-year-old, who spent last term at QPR, is not going to improve Tottenham’s first XI directly, he can provide reliable cover for Danny Rose, meaning that Spurs will no longer have to call upon Zeki Fryers or upset Vertonghen by relocating him to left-back.