Defeat at Kingsholm may have been his side's first reverse in Pool 5, but it put them five points behind Gloucester.
"The only good point for us was that we matched Gloucester try for try. Other than that we had no real answer to them as they dominated territory and possession and were by far the better side," admitted Gaffney.
"Our set-piece has to get better and we have to work out what went wrong at our line-out. We have to win three games now because I don't think four will be enough to win the Pool. I think we are good enough to do that."
Skipper Jim Williams said that Munster's pride had been dented in losing at Kingsholm and "the two things we wanted were control at the set-pieces and good discipline, but they both let us down in the second half.
"I don't think Gloucester are a better team than last season but, like all teams in the Heineken Cup, they are very difficult to beat at home. They knew how to win the game and they played our style of rugby.
"It's going to be another close game at Thomond Park and I think it is going to come down to kicks at goal. It isn't going to be like last year's game - they will be much the wiser coming to Thomond Park and I expect it to be much tougher. The pressure is back on us and we will have to get our heads down and work hard."
"They won't have anything to defend coming to us and it is all for us to do."