Although Slomka says he expects still to be in charge of the club for the start of the second half of the season at the end of January, the club's director of sport Dirk Dufner was unable to provide any guarantees when asked by Sky television.
"I would be dishonest if I were to say that I already know that answer, given that we plan to analyse everything and have some open talks," he said.
"We will approach the issue with the result left open. There is no doubt that we would like to carry on with him, but we will analyse everything and see what we think is the right thing, and what result we arrive at.
"It really will be a long talk, then we will decide."
Slomka is Hannover's longest-serving coach and he led them into the Europa League two years in a row after taking charge in 2009 with the club rock bottom of the Bundesliga and seemingly odds-on to be relegated following the suicide of goalkeeper Robert Enke.
Failure to qualify for Europe at the end of last season already put the pressure on him to deliver European football again at the end of the current campaign.
At the midway stage of the season, Hannover are 10 points adrift of the top six, but Slomka remains optimistic.
"I do expect (to stay) because we have a good relationship and because we have already analysed things a little this week, and certainly we have to carry on doing so to find the right measures for the second half of the season," he said.
"There's a lot of work to do over the Christmas and New Year. We've got to make sure the players go on their holidays with a good feeling so they come back with their minds clear."