Wayne Rooney-Memphis Depay
Wayne Rooney and Memphis Depay celebrate with Anthony Martial in Manchester United's 3-2 victory over SouthamptonGetty

Diego Forlan has urged Manchester United manager Louis van Gaal to sign more strikers to put up a challenge on all fronts. The Old Trafford club have Anthony Martial and Wayne Rooney as the first choice strikers in the squad after allowing James Wilson join to Brighton and Hove Albion on loan for the remainder of the season.

The former Barcelona and Bayern Munich manager sold Robin van Persie and allowed Javier Hernandez to leave the club in the summer. He also decided against signing Radamel Falcao on a permanent transfer after a disappointing loan spell last term. The latter joined Chelsea on a season-long loan from AS Monaco.

The Uruguyan, who was at United from 2002 to 2004 has advised his former club to find a long-term replacement for 30-year-old Rooney. Forlan also believes that the England international does not have the legs to play throughout the season.

"In my opinion I think they need to have more strikers. Rooney is a great player but he is getting older and is playing in every position. He can't play every game," Forlan told Omnisport, as quoted by Goal.com.

"In England, with all the competitions, you play more or less 60 or 65 games per year. So it is a lot of games. You travel a lot so you need more players. Maybe sometimes you will get more players injured so you won't have this player [available] for a couple of months.

"So a team where you play so many competitions and you have so many games, you need more strikers."

Forlan on Club World Cup final

As Argentine outfit River Plate face European champions Barcelona in the 2015 Club World Cup final in Japan, Forlan believes the South American club have the ability to beat the La Liga giants and lift the trophy on 20 December.

"The current River side are a good team, the best in South America with an excellent young manager. Marcelo Gallardo. He played for Argentina, River Plate and then Monaco in Europe, plus Nacional, the rival team to my Penarol in Uruguay," the former United man told The National.

"He started his managerial career at Nacional and joined River last year. He's been a big success, the first person from River to win the Copa Libertadores as a player and manager.

"The Uruguayan influence is also found in forward Rodrigo Moura up front. Leonardo Pisculichi is another top player, an attacking midfielder. Javier Saviola is well known and could come up against his old team Barcelona, but he's 34 now and doesn't play every game," he added.