After losing 3-0 to both Bayern Munich and Benfica, Barca sit bottom of Group E with two games against Kiev up next, the first at Camp Nou on Wednesday. Barcelona last went out in the Champions League group stage 21 years ago.
"Tomorrow we are playing for our future in this Champions League," said Koeman. "After losing two games, we have to win to have a chance of going through. There is no other option." Koeman must decide whether to play Ansu Fati from the start against Kiev, with a 'Clasico' against Real Madrid to come on Sunday.
Fati has lifted the mood at the club since returning from 11 months out through injury. He scored on his first game back against Levante last month and struck another goal in a 3-1 win over Valencia on Sunday.
There have been concerns the 18-year-old could leave when his contract expires at the end of the season but Koeman said an agreement is now close. "The only thing I know is they are close to renewing Ansu Fati's contract," said Koeman. "This is very important news. We are talking about a young, high-quality player who has to shape the future of this club."
