Wanderers were flying high in third place a month ago after five wins from six games but the Black Country club have now plummeted to 13th in the Championship table having failed to win any of their last five.
Home matches against Brighton, Nottingham Forest and Millwall now sandwich a trip to Watford, and midfielder Doumbia told the club's official website: "I think we have been below par in some of the last few games.
"We have had some very good possession but have come across a number of teams who have been able to stop us playing. Technically I think we are superior to a lot of teams in this division but the physical side has not been there in recent games and we need to find that balance.
"I think maybe the last five teams have done their homework and have been physical enough to stop us. I think maybe they can ruffle us by stopping us playing.
"I feel we will overcome it because we have strong players as well and just need to find the right balance between the physical and technical sides of the game. We maybe haven't had that in recent games but we can find it and if we do we will pick up points."