Thomas Vermaelen is close to a £15 million move from Arsenal to Barcelona after a proposed deal with Manchester United fell apart.
United wanted to sign the centerback but Louis van Gaal refused to include a player in return.
Arsène Wenger has steadfastly refused to sell to their rivals unless a swap deal could be agreed and Van Gaal is not prepared to consider that.
Vermaelen, who arrived from Ajax in 2009, made 21 appearances for Arsenal last season.