The Aston Villa winger was substituted after just 40 minutes against Sheffield Wednesday on Saturday.
Wolverhampton Wanderers have earned plaudits for their impressive start to the season.
The Derby County coach is among the favourites for the Sunderland position.
Kevin Phillips knows Rangers striker Joe Dodoo from his time at Leicester City - and should consider a reunion at Sunderland.
Sunderland legend Kevin Phillips has been installed as one of the early favourites to succeed Simon Grayson at the Stadium of Light.
Derby coach Kevin Phillips among the former Sunderland players who could replace Simon Grayson as manager.
Glasgow Rangers forward Martyn Waghorn has been linked with a move away from Ibrox and to Sunderland in the summer transfer window.
Middlesbrough, Sheffield Wednesday and Norwich City are all among the promotion contenders in the Championship.
After missing out on Derek McInnes, Sunderland are still looking for a new manager - and Kevin Phillips is among the favourites.
The Derby County coach is reportedly keen on taking the manager role at Sunderland.