The Tigers' reward for finishing as FA Cup runners-up to Arsenal is a place in the Europa League, but despite their season starting as early as July, Steve Bruce's side are convinced they will cope with the additional games.
It could be a busy start to the season for Hull with the first leg of their Europa League third qualifying round tie being played on July 31 and the second leg on August 7.
The new Premier League season starts on August 16 and if they make it to the play-off round they will have another two games to play before the end of August.
But despite an early return to the training ground, City defender Rosenior is looking forward to playing in Europe.
He told Sky Sports News: "You have aspirations to have a great career and part of that is playing in European games.
"It's fantastic for Hull, it's the first time we have been involved in European competition, we had a good season last year and it gives us something to look forward to next season."
Midfielder Huddlestone added: "I think it will be difficult going into the games at the end of July, it is something nobody is used to, but these days the lads even in the off-season have to prepare themselves fitness-wise ready for the pre-season.
"A few years ago you would use the pre-season to get all your fitness, nowadays the lads have got to do it in their off-season and come back relatively fit."