Trailing 2-1 from the first leg, Mikel Arteta was pessimistic over the duo's fitness after they missed out against Newcastle United - despite their returns to training - while David Luiz succumbed to a hamstring injury at St James' Park.
However, Pierre-Emerick Aubameyang returned to the first XI with a goal at the weekend and will lead the line with confidence, while Granit Xhaka and Rob Holding should deputise for the injured Tierney and Luiz, although they have not been ruled out just yet.
Dani Ceballos will serve a suspension for two bookable offences in the first leg, so Thomas Partey will likely be partnered by Mohamed Elneny, who struck his first Premier League goal against Newcastle on Sunday.
Gabriel Martinelli impressed on the left-hand side at St James' Park but should drop out for Nicolas Pepe, whose second-half penalty in the first leg kept the Gunners' dreams of European silverware alive.
Bukayo Saka and Emile Smith Rowe were also benched at the weekend but could displace Willian and Martin Odegaard in the first XI here, while Calum Chambers could replace wantaway right-back Hector Bellerin once more.
Arsenal possible starting lineup:
Leno; Chambers, Holding, Gabriel, Xhaka; Partey, Elneny; Saka, Smith Rowe, Pepe; Aubameyang