The Canaries won just two of their opening 10 fixtures, but have picked up three wins in their last six games to keep themselves five points above the relegation zone.
Meanwhile, the Swans are just two points ahead of them in 10th and are coming off the back of a midweek trip to Switzerland in the Europa League.
"Of course this is a tougher game than it would have been a month ago," the Danish coach told reporters.
"Circumstances change. It's the same team, the same pitch, the same ball, but in a different moment and circumstance.
"If they beat us, they go above us by a point. That's how it is, maybe a month ago or in a month's time it would be different but we are not playing last month, we are playing Sunday."
Swansea lost 1-0 against St Gallen on Thursday but still managed to qualify for the last 32.