The Belgium defender could complete a move to the Nou Camp over the weekend.
Arsenal boss Arsene Wenger on Thursday suggested the club's preference was to sell the defender abroad, rather than to a domestic rival, with Manchester United rumoured to also be interested.
Club captain Vermaelen, who joined from Ajax in 2009, made 21 appearances for the Gunners last season.
Niggling injuries and the form of Laurent Koscielny and Per Mertesacker limited his impact.
However, despite being an unused substitute at Wembley, he did lift the FA Cup in May as Arsenal ended their nine-year trophy drought.
The 28-year-old has made 150 appearances in all competitions, scoring 15 goals for the Gunners.
Speaking on Thursday ahead of Sunday's Community Shield with Manchester City, Wenger revealed interest from United and others.
Wenger said: "Have we received bids? Yes. I can't tell you who from but you will know very soon.
"Are Man United one of the teams to have made an offer? I think they could be in the group.
"Ideally, yes, we would like to sell him abroad and that is an option for us.
"I don't want to say how many offers we have but we have offers from abroad as well."
United are understood to still be interested, although a swap deal would not interest them, with rumours Arsenal enquired about defender Chris Smalling and striker Javier Hernandez.
Now it seems the Nou Camp, and not Old Trafford, is Vermaelen's likely destination.
Wenger believes it is important for Vermaelen to play.
"He could leave, it could happen, I've said that since the start of pre-season," the Frenchman added.
"He needs to play now. He has shown an outstanding attitude but he is in a position where we wouldn't stand in his way if he finds an interesting opportunity."