Gabi says leaving Atletico Madrid was the hardest decision he has had to make in his career, with the club captain heading to Qatar.
The 34-year-old has agreed to join Stars League side Al Sadd, where he will join forces with another La Liga icon in former Barcelona star Xavi.
Gabi announced his move at a news conference on Tuesday and said it was the right time to move on.
"It's a difficult and emotional day, thanks for helping me make the hardest decision of my career," Gabi said.
"I've been thinking with my heart since I was 12 and now I have to do it with my head.