Adelaide United have bolstered their squad for the upcoming AFC Champions League after signing former Newcastle Jets midfielder Adam Griffiths on a six-month deal.

The 30-year-old midfielder joins having left Saudi Arabian outfit Al Shabab and brings plenty of continental experience, having been part of the Jets side that reached the last 16 in 2009.

"Adelaide are a good team, obviously they haven't done so well this year but their performances have been pretty strong, they just haven't been able to get the goals that they've needed," Griffiths said. "I'm just looking forward to playing for Adelaide, doing well and concentrating on playing some football again."

Griffiths could also feature in the final two games of the A-League season and boss Aurelio Vidmar underlined what he can bring to the Reds squad. "We're really pleased with signing Adam," he said.

"He's an experienced player, and more importantly he's had experience with Newcastle in the previous Asian Champions League so that's an added bonus for us.

"He's got a lot of strength, he's a good passer of the ball, a good reader of the game and we can use him in a variety of roles which is really important. We're really looking forward to Adam rolling up his sleeves and doing his very best for the club.

"Adam's name came across our table about five weeks ago. We also knew at that stage that he was coming back from Saudi Arabia. It's just for the ACL at this point in time, Adam has got other ambitions but we believe it is not out of the question that something might happen in future.

"But for now the most important thing is that Adam is with us through the Asian Champions League, that's going to be a big positive for us and it will also help with the stimulus and mentality amongst the group in a healthy way."