United have alienated a section of their fans and former players with a series of soporific displays this season and were booed by their supporters at home on occasions.
Robson, United's longest-serving captain, feels the fans are justified in being frustrated with the dour playing style of a club famed for entertaining fans with their attacking flair.
In an interview with Reuters, the 59-year-old said the players could do more to woo the fans again.
"Lot of people will always blame the coach but sometimes the players have to express themselves a little bit more," the former England captain said. "The players have to take that responsibility.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"We are in the entertainment business and that's why Manchester United have 680 million fans around the world.
"We have to entertain those fans and that's always being part of Manchester United."
United have dominated possession against most opponents but have largely failed to convert it into goals, lacking creativity in and around the 18-yard box.
Robson, who was in Mumbai to inaugurate a football pitch created by Apollo Tyres using recycled rubber, said United currently lacked players who could supply that extra bit of flair.
"Sometimes you need attacking players with a bit of imagination and flair to actually produce that type of football
"At the moment we are just a little bit short of that. We are not far off," said Robson, who scored 99 goals in 461 appearances for United during his 13 years at the club.
"People like (Wayne) Rooney, (Anthony) Martial, (Memphis) Depay and (Juan) Mata -- they have all got great ability and it's just about getting a little bit better."
Van Gaal has won league titles in Germany, Spain and Netherlands and having tightened the team's defence, Robson felt, the 64-year-old was ideally placed to reinvent United's attack.
"When Louis van Gaal first came to the club he wanted to get a good, solid base to the team," said Robson, who has managed Middlesbrough, West Bromwich Albion, Sheffield United, Bradford City and Thailand's national team.
"We have proved this season that we are difficult to score against.
"So now I think Louis Van Gaal will look to be that little bit more attacking and try and get the side to (the level) which the Manchester United fans have always been used to."
United are currently fifth in the Premier League table, seven points off leaders Arsenal, but Van Gaal believes his team can still win the title.
A less optimistic Robson predicted a top four finish for the side with Manchester City and Arsenal as his picks to win the league.
He ruled out second-placed Leicester City winning the League but tipped them for a Champions League slot.
Robson also expects England to do well at this year's European Championship even though he doest not really see them beating world champions Germany or Spain.
"I think this time we have quite a good chance of doing well in the competition.
"We have young players with a lot of pace in the team and we have good fitness.
"I think Germany are still the favourites. Spain are always difficult to beat. I will say after Germany and Spain England have got a chance."
(Editing by Amlan Chakraborty)
