Atletico Madrid coach Diego Simeone admitted star forward Antoine Griezmann's lean spell in front of goal has had a profound effect on the Spanish giants' stuttering start to the season.
Twice finalists in the past four seasons, Atletico need to beat Roma on Wednesday and Chelsea away in two weeks' time to stand any chance of progressing to the Champions League last 16.
Even then Atletico would also need Qarabag to at least hold one of Chelsea or Roma in their final two group games.
Griezmann hasn't scored in eight games and was jeered off when he was substituted by Simeone towards the end of Saturday's 0-0 draw at home to local rivals Real Madrid that also left Atletico 10 points off the top of La Liga.
"It is normal that he is worried," Simeone said on Tuesday.
"He needs a goal. It has been many games since he scored, he's had chances but when he doesn't score, he suffers, as do the team and the fans.
"We have to give him confidence and calm. At some point it will all return to normal."
Griezmann has been Atletico's top scorer for the past three seasons, as well as winning the golden boot at Euro 2016 with France, but admitted to French TV station TF1 this week his form was a concern.
"I have to improve and find my form. There have been games where I haven't had one shot on goal and that is my problem," said Griezmann.
However, he has angered some Atletico fans by publicly flirting with a move away before agreeing to stay and signing an improved contract when the club's appeal against a transfer ban was rejected in June.
- Koke backs Griezmann -
Midfielder Koke is sure, though, Griezmann will be backed with Atletico's Champions League hopes at stake.
"The fans will support Griezmann. No one likes the situation at the moment, not him nor his teammates," said the Spanish international.
"He knows what to do and he will give his all as always. He can play well or not, but he will always have the support of his teammates and fans."
Atletico will know if they have matters back in their own hands before kick-off at the Wanda Metropolitano (1945GMT) with Chelsea kicking off against Qarabag at 1700GMT in Baku.
However, should the Premier League champions slip up, Roma could guarantee top spot in Group C with their seventh straight win.
"After a difficult first game we've improved, we could even have won in London," said Roma coach Eusebio Di Francesco, who expressed his surprise at Atletico's plight after they dominated a 0-0 draw between the sides to open the group in September.
"Our objective is to get through to the next round and try to do it as group winners."
Roma midfielder Diego Perotti, though, warned against writing off Atletico having suffered at the hands of Simeone's men plenty during a five-year spell at Sevilla.
"We can't count them out because we know how their coach motivates them and what a bonus it is for them to play in front of their fans.
"We know we have a big chance because even a draw would qualify us, but we can't write them off because I have personally played against Atletico Madrid and know how hard it is."
Stefan Savic is suspended, whilst Simeone is also expected to recall Filipe Luis, Jose Maria Gimenez, Yannick Carrasco and Fernando Torres from the side that started against Real in a bid to end a five-game winless streak at Atletico's new home.