Rosenborg coach Kare Ingebrigtsen has been sacked six days before the Norwegian club face Celtic in the Champions League.
The 52-year-old has been dismissed the day after his side scored a stoppage-time penalty to earn a 3-2 aggregate win over Icelandic champions Valur.
That set up a second qualifying round meeting with the Scottish champions.
Rosenborg are two points behind leaders Brann in the Norwegian top flight, and have won nine of their last 13 games.
Ingebrigtsen took over in the summer of 2014, initially on an interim basis, and has won three successive league titles as well as lifting the Norwegian Cup twice.
Academy director Rini Coolen will take temporary charge and oversee the tie against the Scottish champions.
"It is a surprise for everyone, me as well," Coolen said. "I was told of the situation and have been asked to take over for the next couple of months.
"The next game is against Celtic and the most important thing is to get to the next round, and that is very important."