Youngs is one of eight Tigers players in the 32-man group which will prepare for the upcoming Tests against Fiji, Australia, South Africa and New Zealand.
Cockerill, the Tigers director of rugby, said: “Tom has done a lot of hard work to get this far and we're delighted for him that he has started to establish himself with Leicester and has now earned a call from England.
“He is a good lad, he has an excellent attitude to his work and he's making progress all the time.
“He's started every game for us so far this season because we feel a run of games is important to his development. He’s been playing very well.
“He's still learning in his position, but he will do that more with every game he plays and we see him getting better and better.
“We wish him well, along with the rest of our international players, during the autumn series and look forward to their safe return to Tigers in due course.”