By Wayne Veysey
First-choice goalkeeper Wojciech Szczesny is set to miss out for the second game in succession following his deputy's fine display in Wednesday's win at Bayern Munich.
Arsene Wenger said Szczesny had been taken out of the firing line because he was "mentally" fatigued and the 22-year-old did not even travel with the squad to Germany.
Goal.com has learned that Fabianski will be handed the keeper's jersey for the pivotal trip to Swansea as Arsenal attempt to narrow the five-point gap to fourth-placed Chelsea.
Kieran Gibbs is expected to be rested for the Liberty Stadium clash after picking up a thigh injury in Munich, with Nacho Monreal likely to get the nod over Thomas Vermaelen for the left-back berth.
Wenger is otherwise set to stick with the back five who were so impressive as Arsenal were eliminated from the Champions League on the away goals rule. Centre-back pairing Per Mertesacker and Laurent Koscielny are poised to start, with Carl Jenkinson at right-back.
Fabianski started his first Arsenal game for 13 months in Munich but did enough to convince Wenger that he deserves another chance this weekend.
The 27-year-old has started only 63 games in six years at the Emirates Stadium and is available on a free in the summer, when his contract expires.
There is no suggestion at the moment that he will be offered a new deal as Wenger targets a proven goalkeeper in the next transfer window.