"It was very disappointing the way we started the game, it was poor," Robson told Sky Sports after the 1-0 defeat.
"We were very tentative, the players showed nerves because of the position we are in the league and that's the way the lads performed in the first half.
"In the second half, there was not much to lose and we put on a good performance but we could not get a break.
"We can't start game the way we started. We didn't lift the fans or give them anything to cheer about.
"We have conceded a goal on another set-play and we are going to get beat if we keep conceding from set-plays.
"The fans are going to be disappointed, we have won just one in 17 and they want to come here and be entertained.
"Of the first half, the fans have seen too much of that this season and we have got to give them something to cheer about."