The Gunners are experiencing a busy transfer deadline day as they look at both additions and departures.
They are keen to move on Icelandic shot-stopper Runarsson, who has struggled to live up to expectations since he made the switch to north London from French club Dijon.
And the 26-year-old could have an exit route from the Emirates Stadium as Arsenal are talking with Leuven over a potential deal.
A switch to Belgium could allow Runarsson an opportunity to get his career back on track and play regular first team football.
The goalkeeper has made just six appearances since he joined the Gunners and struggled to convince.
And with Bernd Leno and Aaron Ramsdale at Arsenal, he is facing a season of limited game time if he stays put.
Runarsson still has another three years left to run on his contract at the Emirates Stadium.
