United are brimming with confidence ahead of Sunday's derby against champions Manchester City having won five straight league matches - including notable victories over Liverpool and Tottenham.
That run has seen United leapfrog City in the Premier League table and they arguably start the match as favourites at Old Trafford.
Centre-back Jones admits that it took the team time to adapt to Van Gaal's style, but is confident that every player is now fully aware of what is expected of them.
"Every player is well aware of the philosophy of the manager and the way he wants his teams to play," Jones told Sky Sports.
"I think that's why we've been hitting such good form lately. Every player now understands their role in the team. It's more stable.
"Players know what they're doing, day in, day out. Players like routines. They like to know what they're doing in the week and in training.
"You can tell by the performances of late that the players are happy and enjoying it. There's a real buzz around the training ground.
"A lot of people wrote us off. We knew the capabilities and qualities in the dressing room. It's a big game at the weekend, we've got to go out and win the game."
