"It has been a very difficult few weeks for me, but I am glad it all has ended up in a very positive way," he said on Sunday after ending weeks of speculation regarding his exit from Al Jazira.
Diaky, 31, had previously expressed his desire to move to Al Ahli after becoming unhappy at being left out of the Jazira starting XI toward the end of the last Pro League campaign, under the Spanish coach Luis Milla.
"I had to re-think on my earlier decision of a move to Ahli after meeting officials from Al Ain," he said.
"It has all panned out well for me to play for the league champions. All that took place before is now behind me. My thoughts are of a fresh start and preparing for the season ahead with my new teammates.
"I have been playing in the UAE for a long time and have a pretty good idea of my new team. I am privileged to play for them and some excellent players are around me.
"The opportunity to play for Al Ain has provided me to set new goals and more motivation. I want to do my best and help them win all the trophies."
Diaky leaves Jazira after nine years, with one year still remaining on his contract with the capital club.
"I have had a great time at Jazira and will be taking a lot of good memories along with me," he said. "Nine years is a very long time to be in a club. Jazira gave me a lot of joy and a good life to lead, for which I will be ever grateful to them. I wish I will have some success at Al Ain."
Diaky, born in Ivory Coast, was granted UAE citizenship after his first season at Jazira.
He arrived at the Mohammed bin Zayed Stadium from the Tunisian club Esperance Tunis in 2005, where he plied his trade for three years after a season with ASEC Mimosas in his homeland.
Jazira finished third in his first two seasons and runner-up twice the next three years before winning the league and President's Cup in 2011, the first time they won a major trophy in the history of the club.
They retained the President's Cup in 2012 but finished a disappointing fourth in the league, 20 points behind Al Ain, in 2013.
Jazira ended their last campaign trophy-less, finishing third in the league, reaching the last four stage in the President's Cup and losing to Ajman 2-1 in the Etisalat Cup final.
"Al Ain have a great track record, so I am very hopeful of winning a few medallions with them and I wish I can contribute in their success," Diaky said.
Also yesterday, Jazira officials dismissed speculation that Subait Khater, the veteran midfielder, also would be leaving the club, perhaps intended for Sharjah.
Khater and Diaky for the past several years had formed a partnership in the middle of the field for Jazira.
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