The Dutch coach admitted his team face a battle to haul themselves into the title race in the second half of the season, despite starting 2021 in fifth.
La Blaugrana look poised to secure a Champions League spot at the end of the campaign, but a ten point gap behind league leaders Atletico Madrid looks like a insurmountable barrier.
Koeman stated he is happy that his squad are improving but confirmed they need their rivals to slip up in the months ahead.
“This month is very important for our aspirations as we have many away games, but if we win them, I think we can fight for the league,” he told a post match interview with Marca.
“We have seen here (at Huesca) that it’s not easy to win away from home.
“If our rivals catch a bad result the gap can be shortened, but it depends on our victories also.”
Barcelona face a busy run of games before the end of December, with the potential for 12 points if they can pick up four wins.
However, Koeman’s side face three consecutive away games, with trips to Athletic Club, Granada and Elche before hosting the Basque giants at the Camp Nou on January 31.