Actor Tom Hanks has added his voice to those protesting the artificial turf surfaces that Canadian venues will use at the upcoming 2015 FIFA Women's World Cup in Canada.

"Opinion: Women's World Cup is the best Soccer of the year," Hanks tweeted to his 8.73 million followers on Friday. "Hey FIFA, they deserve real grass. Put in sod."

The use of turf at all six Canadian venues for the upcoming major tournament has been a contentious issue for some players, including American stars Abby Wambach and Alex Morgan. A group of 40 international players recently sent a letter to FIFA and the Canadian Soccer Association threatening legal action, arguing that requiring women to play on artificial turf is discriminatory.

The letter claims that no men's World Cup final has ever been contested on an artificial surface.

FIFA president Sepp Blatter said at a news conference in Toronto earlier this month that tournaments held on turf are a reality of the future, and that the quality of today's turf is much better than the old green carpets used in the past.

But in the letter, players say that even the better quality turf used today still poses a greater risk for injury than playing on a natural surface.