The 28 year old will come in as the club's Asian players because of his dual Uruguayan-Australian citizenship and becomes the second foreign player to join Dubai after Magrao, the Brazilian midfielder, who moved after three seasons at Al Wahda.
"The offer from Dubai was too good to refuse and Richard is hoping that by moving there he will become much more visible to Australia's coaching staff," Porta's Sydney-based brother and adviser, Gonzalo, was quoted as saying on football website theworldgame.
"The club is very ambitious and they kept coming back to us with improved offers until it became impossible for him to refuse."
Porta is still hoping to play for the Australia national side and there is a growing call for him to be offered a cap to strengthen the attacking options, and possibly as early as the international friendly match with Scotland in Edinburgh on August 15.
"Richard is aware that some of the Socceroos players are now based in the Middle East and hopefully that can also work in his favour," Gonzalo said.
"He would dearly love a call-up and has certainly not given up hope. They were certainly following him when he was last there and I am sure that will happen again.
"If he does well then hopefully the recognition will come."
Porta was on the radar during his injury-hit eight-game spell under Maradona.
Holger Osieck, the Australia coach, is said to have recently requested a DVD of his exploits in Uruguay, where he topped the scoring chart with 17 goals for Nacional after his contract with Al Wasl was terminated.
Porta will work under Rene Marsiglia, the new French coach of Dubai, who is aiming to improve on last season's unimpressive 10th place in the Pro League.
"The club has big ambitions to become a force in the region and they see Richard as somebody who will provide the goals they will need," Gonzalo said.
Elsewhere, German Herrera, the Brazilian club Botafogo's Argentine striker, has joined Emirates.
The Ras Al Khaimah club are strengthening the squad as they will be competing with Sharjah, Al Shaab and Al Dhafra in the play-offs for two spots in the expanded 14-team Pro League this season.
Al Shabab have signed Luiz Henrique da Silva, the Brazilian midfielder, who will link with compatriot Ceil along with the Uzbek, Haydarov Azizbek.
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