Van Gaal has made it clear he wants United to line up in the 5-3-2 formation he used during the latter stages of the World Cup with Holland.
With only three centre-halves on his books, Van Gaal has already admitted he needs reinforcements.
The former Holland manager is actively pursuing Thomas Vermaelen, Stefan de Vrij and Mats Hummels, although signing the latter is proving problematic as Borussia Dortmund do not want to sell another star this summer after losing striker Robert Lewandowski to Bayern Munich.
Smalling started 21 Premier League games last term under David Moyes and he has looked sharp in both friendlies on United's tour of the United States and he thinks Van Gaal's system suits him well.
Smalling said: "Being part of that formation means you have a lot of responsibility.
"We really have to go out there and attack and be nice and aggressive. I would like to think that's my game.
"I played in a back three when I was younger, not since I turned professional, but we are all picking it up and enjoying it.
"Communication is key, but we get on well so that's not really an issue."
Van Gaal maintained his 100 per cent record as United boss with a 3-2 win over Roma on Saturday, but he was unhappy with his team's performance in Denver, accusing them of wasting possession.
Despite having just three days' rest after the World Cup, Van Gaal has wasted no time implementing the rules that he thinks will turn United into winners again.
The players have been told they must speak English to each other in an attempt to improve communication on and off the pitch.
Rectangular tables have been replaced with circular ones in the dining halls on tour so the players are more likely to chat and bond over meals.
Tour plans have been amended so United stay in hotels near to their training facilities and Van Gaal sits down with his coaches at 10:30pm every night to discuss the players' progress.
"It's all down to fine details," Smalling added.
"He has the whole overview - on how we play, how we take set-plays, how we eat, how we rest. He has that all in hand."
Smalling clearly admires his new manager greatly.
"He is a man who requires a lot of respect and we give him that because of what he has done and what he is like," the England defender said.
"We are all trying to impress him, whether it's in training or in the hotel with how we conduct ourselves.
"He is a man we can learn a lot from."
Smalling admits the team should not be immune from criticism despite recording their second successive tour win.
"At times we were a bit sloppy and we need to work on that to make sure that we tidy that up," he said.
But there could be no criticism from Smalling, or any of his team-mates, towards Wayne Rooney, who scored a stunning curler from 25 yards to put United ahead in Colorado.
"That's what special players can do," Smalling added.
"He turns there and you think he has nowhere to go, but then it's in the top corner.
"It's that kind of class we are going to need this year."
United flew to Washington DC on Sunday ahead of their next match in the International Champions Cup against Inter Milan, which takes place on Tuesday.
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