Callum McGregor acknowledged that Celtic's bid for a 10th successive Scottish Premiership title is out of their hands but refused to give up hope.
The Hoops are 21 points behind Old Firm rivals Rangers at the top of the table with three games in hand but with the Ibrox side yet to taste defeat in 23 league matches.
Ahead of the home game against Livingston on Saturday, where Celtic will again field a makeshift side due to Covid-19 issues, McGregor, who will be captain in the absence of Scott Brown, said: "We have to try to stay as positive as we can.
"We know it is a big task now. We are going to have to win every game and still look for a couple of favours as well.
"We know it is a difficult task but we know we can't lose hope or lose faith, or anything like that, we have to keep fighting.
"You never know in football, things can change very quickly like they have done and I have seen it happen many times.
"We have to, as a club, look forward in a positive way and get back to winning football matches."
Boss Neil Lennon, his assistant John Kennedy and 13 first-team players are still self-isolating as close contacts of injured Christopher Jullien who was confirmed to have contracted Covid-19 after returning from a training camp in Dubai.
A weakened Celtic side drew 1-1 with Hibernian on Monday night and now face a Livi team that have won eight in a row since David Martindale took over from Gary Holt.
McGregor said: "Obviously it has been a difficult week for the club, a lot of things up the air.
"Jullien tested positive and there were concerns there right away to see if he is OK and feeling well.
"That is the first thing. Thankfully he is OK, he hasn't got any symptoms which is good.
"It is just counting the days to get the boys back in."
