Arsenal boss Arsene Wenger sees Fabianski as the long-term No 1 and the man to replace Jens Lehmann.
Fabianski’s agent Martin Wiesner said: “We are very close to a deal with Arsenal — an agreement is there between both clubs.
“We just have to arrange some details of his contract at Legia and with Arsenal.
“Lukasz had medical tests on Tuesday and he has flown back to Poland to play for Legia. I expect him to return to London later this week to have more talks.
“Lukasz has had three offers but we are close to completing the deal with Arsenal.”