Valérien Ismaël says defeat at QPR is a “difficult one to take”.
The Baggies were beaten by a late Charlie Austin header at the Kiyan Prince Foundation Stadium in what was an evenly-contested encounter in west London.
Ismaël said: “It’s a difficult one tonight.
“It was a good performance, especially in the first half.
“We didn’t manage to create the big chances because the last pass and the crosses weren’t good enough.
“QPR raised their game in the second half and they applied plenty of intensity and pressure, but we managed to initially withstand it.
“We gained a bit of momentum when Daryl Dike came on. We felt as though we were on the right path.
“After that we should have had a penalty for a foul on Conor Townsend. It’s very frustrating because it’s two games now where I feel we should have had two penalties and we could’ve had six points from them.
“I think we would’ve won the game if the ref had given the penalty.
“We conceded the goal right at the end and it’s such a big frustration.
“The other big frustration is that we cannot play with our best players. We have injuries and suspensions. We have to manage it every game.
“When you have the best players on the pitch and on the bench able to come on you can have an impact on the game.
“At the minute it’s difficult because we are not able to get all our key players together and we’ve had that problem for many, many weeks now.
“We need them all back to create more momentum.
“I understand the criticism because we are not satisfied with the results.
“At some point, we need to understand our situation because we can’t play with our strongest team.
“We need to get our key players back.
“Daryl Dike impressed when he came on and that is a big positive.
“We have to keep going and we have to keep challenging.”