The 44-year-old used to be assistant coach of this weekend's opponents, but insists he does not have split loyalties ahead of the clash at the Rhein-Neckar Arena.
"My likening for them will simmer for the game," he said. "I love my job here in Hoffenheim and enjoy every day I get to work here."
Gisdol is likely to be in command of Hoffenheim for a while to come, given the start the side who only avoided relegation in the final minutes of last season have made.
With six games of the season gone, they are one point ahead of Saturday's visitors, who started the season with European ambitions.
"I'm sure Schalke expected to make a better start to the season and there is certainly going to be pressure on them to get something here," Gisdol said at a press conference.
"We've got to face up to them and react. We've learned a lot from our first games and we know what we can do really well, and we want to show that on Saturday."
Schalke want to show that their 4-0 defeat at home to Bayern Munich a week ago was only a one-off.
"We know how important this game is," said their coach Jens Keller, who is hopeful of welcoming Kevin-Prince Boateng back into his side after he missed the 3-1 DFB-Pokal win in Darmstadt.
Julian Draxler is not likely to be fit, on the other hand, but Max Meyer can expect to play a part following his first professional goal in midweek.
Before the game, a tribute will be paid to Hoffenheim midfielder Boris Vukcevic, who was involved in a car accident a year ago to the day and is still on the road to recovery.
"Boris was one of my under-17s at Stuttgart," Gisdol said. "I know him very well and we are going to remember how well Boris played and how he always went the extra mile."
Hoffenheim have left a space in their squad open for the Bosnian, should he make a full recovery. The 23-year-old will not be present in the stadium this weekend, but his parents say he plans to pay the team a visit in the coming weeks.