The Brazilian was told his contract would not be renewed by the Reds earlier this week and the Phoenix were quick to pounce to secure his services.
“He’s someone (coach) Ricki Herbert and I had been looking at for a while and he’s exactly the type of player we need. What we found this season is the need for an attacking midfield-style player. We had (Brazilian guest player) Fred for a few weeks and we really saw the difference he brought to the team,” said Phoenix chief executive Tony Pignata.
“The agenda was to go out and get an attacking-minded midfielder and Diego really fits the bill.
“He’s a quality player and he’s done a great job for Adelaide, particularly during their recent Asian Champions League campaign. But these things happen and Diego is certainly looking forward to coming to Wellington and continuing to play in the Hyundai A-League.”
The 29-year old has signed a two-year deal.