The Wales international began his career at Prenton Park before going on to play for the likes of West Brom, Cardiff and Wigan.
But the 33-year-old has been without a club since his last professional appearance for Cardiff in their play-off semi-final defeat to Reading in May 2011.
Moore confirmed on Tuesday that Koumas' love for the game has been rekindled and he will be assessed in the coming weeks.
"We got a phone call from his agent asking if we'd have a look at him," Moore told the club's official website. "He fell out of love with the game, but he's back in love with it and he wants to come back.
"We said to bring him in and we've got sports science guys working with us now who will monitor his fitness.
"In two or three weeks time when he's fit and can play then who knows what might happen, but at the present time he's here to train and we'll have a look at him.
"It was supposed to be top secret, but nothing lasts too long."