The Belgian playmaker has not featured in Albion's first two Premier League matches following a falling out with boss Tony Pulis, who is thought to be weighing up whether to let Chadli leave amid interest from Swansea.
Chadli is likely to feature as part of a much-changed West Brom line-up for the second round tie as Pulis looks to give some of his youngsters some game time.
The likes of Rekeem Harper, Jonathan Leko and Kane Wilson have been included in the squad for both Premier League matches so far this season but the young trio could start on Tuesday night, along with Boaz Myhill and Salomon Rondon.
James Morrison may be involved for the first time this season as he steps up his fitness following a knee injury but Hal Robson-Kanu will be missing after he lost his appeal against the red card picked up at the weekend.
Gareth McAuley, Jonny Evans, and Claudio Yacob are all set to miss out with knocks.