Re: call up players that are in juniors to the nhl.

No, there is no way. You have to wait until the next season. Not sure exactly if the game handles this correctly, but players that are drafted from a CHL-team, can only leave the juniors if they turn 20 before december 31st the season in question (when you want to call him up).

But in short, most likely you have to wait until the next season.