Merson was back at The Holte Suite last week to host a 'Q&A' with 300 Villa fans eager to discuss the future of Barry, as Liverpool try to prise the England player out of the Midlands.
He said: "I have known Gareth a long time and rate him the most talented player I played alongside at Villa. He is an absolute natural with a fantastic left foot.
"But one thing I also know about him is that he loves his football. He is only happy when he is playing week in, week out.
"I am not sure that is going to be the case at Liverpool. Naturally, he is going to be tempted by the prospect of Champions League football.
"But you never know what can happen - Liverpool have got a qualifying round to get through and what happens if they mess up in that?
"We can it here all night and talk this out. There are loads of plusses for going to Liverpool and loads of plusses for staying at Villa.
"The grass is always greener and you can't blame Gareth for being tempted.
"I would like him to stay here of course but I honestly think he will leave before the start of the season."