Barcelona's Pedri celebrates after scoring his side's opening goal against Celta Vigo. [AP]

Barcelona will be looking to give their Champions League knockout-round hopes a huge boost when they welcome Inter Milan to Camp Nou for a key encounter tonight.

The Catalan outfit are third in Group C, three points behind second-placed Inter, with the Italian giants recording a 1-0 victory when the two teams locked horns at San Siro last week.

Barcelona failed to progress through the group stage in the Champions League last season, and the club is facing that possibility again this term, with a total of three points from three matches leaving them third in Group C, three points behind second-placed Inter and six from leaders Bayern Munich.

Xavi's side opened their group-stage campaign with a 5-1 victory over Viktoria Plzen on September 7 but have lost their last two in the competition, going down 2-0 at Bayern before the loss to Inter at San Siro, with Hakan Calhanoglu scoring the only goal of the contest late in the first half.

Barcelona will be aware of the importance of winning today's contest, and they will be pleased to be back on home soil, having not lost at Camp Nou in any competition since May.

While it has been a struggle in the Champions League this season, the Catalan outfit have been excellent in La Liga, making it seven straight victories on Sunday night courtesy of a 1-0 success over Celta Vigo, with Pedri scoring the only goal of the contest in the 17th minute.

Barcelona will be looking to Robert Lewandowski for inspiration. The former Bayern Munich forward netted a hat trick against Plzen but was kept quiet against his old team and was largely anonymous in the first match against Inter.

"It's an important match in which we will have everything on the line," Barcelona defender Marcos Alonso said after the Catalan club beat Celta Vigo 1-0 at home Sunday for its seventh straight Spanish league victory.

Inter will be hoping the victory against Barcelona signalled a turning point in its season after a mediocre start to the domestic campaign which saw it lose four of its opening eight Serie A matches before that important Champions League win.

The Italian giants progressed through the group stage of last season's European Cup but were beaten by Liverpool in the round of 16, and they have not made it past the first knockout round of the competition since reaching the final eight in 2010-11.

The Black and Blues suffered a 2-1 defeat when they last travelled to Camp Nou in the group stage of the 2019-20 competition, but Barcelona have lost three of their last six Champions League matches in front of their own supporters, which should hand the visitors confidence.