It's not something he has publically conceded but following the 0-0 draw at home to rival Spurs, it's something that has an air on inevitablity about it.
"We were looking to win the game," said the Italian.
"But we have to give Spurs credit,they defended well.
"It will be difficult (to finish fourth). spurs were always going to be a difficult side to play.
"But we will try to win our last eight games.
"To finish in the to four is very important for this club - it's vital for the future of the club.
"We might have to win all our remaining games. but we will take the next game and the one after that."
Di Matteo explained that the first half performance was not good enough.
"We were too slow and did not move the ball quickly enough to our striker," he said.
"Teams come to the Bridge and get many men behind the ball.
"Cech made crucial saves, but we hit the post too and had a very good penalty turned down"
Di Matteo was a furious in fact: " Ramais was taken down by Assou-Ekotto innthe 67th minutes," fumed Di Matteo.
"The Ramires penalty was 100 per cents a penalty. it is not in doubt, it was a clear penalty."
Chelsea also have a midweek game, away to Benfica in the Champions League.
"We will assess the fitness levels of the players to see who will play against Benfica," he said.
"But John Terry and Didier Drogba both came through this game fine."