Slaven Bilic is sweating on the fitness of one of his players ahead of the visit of Sheffield United.
Jake Livermore and Kieran Gibbs contracted coronavirus earlier this month and, while Bilic refused to say who, one is still feeling unwell despite testing negative on Monday.
Sam Field has been battling a knee problem – having recovered from Covid-19 – and could be included in Saturday's squad.
The Blades, the only team below the Baggies in the table, look set to be boosted by the return of Lys Mousset.
The French forward, United's top scorer last season, has been out since suffering a rare toe injury in pre-season. He has resumed training ahead of schedule and may play a part at the Hawthorns, with the Blades still looking for their first win of the season.
Enda Stevens and one other player, who boss Chris Wilder declined to name, are injury concerns for the visitors.
West Brom provisional squad: Johnstone, Button, Gibbs, Ajayi, Townsend, O'Shea, Bartley, Kipre, Ivanovic, Furlong, Edwards, Krovinovic, Field, Sawyers, Diangana, Livermore, Phillips, Pereira, Harper, Gallagher, Robson-Kanu, Grosicki, Austin, Robinson, Grant.
Sheffield United provisional squad: Ramsdale, Foderingham, Baldock, Stevens, Egan, Basham, Lowe, Robinson, Bogle, Jagielka, Ampadu, Lundstram, Fleck, Norwood, Berge, Osborn, McBurnie, Sharp, McGoldrick, Burke, Brewster, Mousset.
