As posted by Fabrizio, Nottingham Forest has parted ways with it's manager Nuno Espirito Santo, these's was a tense situation at the club between him and them, I believe that's the main reason why he was sacked. Nottingham Forest has started off this season with a win, a draw and a lose in three matches. I believe that's one of the major trigger as to why he and the club management has fallen off and it resulted in a sack.
Remember that Nuno Espirito took over the club when they were 17th in the Premier League. Nottingham Forest made it to the top four previous season but dropped back due to some losses at the end of the season. There was a rumour that the club's owner fired Nuno in order to bring in Ange Postecoglou, who was fired by Tottenham after winning the Europa League.
Perhaps it is true that Nuno Espirito played a key role in Nottingham Forest's success last season because we observed that he was able to bring this team back from relegation to seventh place last season. Yet he has only managed to lead the team in three matches in this new Premier League season but Nottingham Forest Football Club has already appointed a new coach and I think they are considering him as Nuno Espirito's successor. In fact this former Spurs manager has experience as he was previously expected to be employed with the German club but but everyone can see that Ange Postecoglou has already signed a contract with Nottingham Football Club.