City's unbeaten run of seven games came to end with a 4-1 defeat at The Hawthorns on Saturday afternoon and Johnson is looking for a quick response in City's next two home fixtures.
"You can't give a team like West Brom a two goal start and then give them another two goals just after half time," the City boss said after the match.
"We are very disappointed but we are not totally distraught after coming up against a very good side who are strong at home.
"We had a little bit of the play but didn't take our chances.
"At 2-0 you know the next goal is vital and they got it.
"We have lost our seven-game unbeaten record and we will now have to rally the troops for the two home games that are coming up."