The early favourite has been former coach Roberto Di Matteo, but it is not believed that the Italian is ready to return to management following his departure from Chelsea last season.
Sky Sports does understand that McInnes, who took charge of Aberdeen earlier this year and has helped turnaround the fortunes of the Pittodrie club, is on their shortlist.
McInnes is still regarded as a legend at West Brom after he spent three years with the club as a player from 2000.
Martin Jol, out of working after leaving Fulham, is another former West Brom player who has emerged as one of the early contenders.
Former Manchester United number two Phelan is believed to be on their radar and he could form a management team with former Baggies favourite Michael Appleton, who is out of work after leaving Blackburn earlier this year.
Another contender with United connections is Ole Gunnar Solskjaer, coach of Molde, whilst Paul Clement - brother of former West Brom favourite Neil - and now at Real Madrid has also been linked.