Although PSG and Manchester City have grabbed all the early European attention, Lionel Messi keeps one eye on Real Madrid.

Following two successive scoreless draws away from home, Barca remain top of Group D, three points ahead of Juventus, and with passage to the knockout phase already secured.

Although Pep Guardiola’s City and French giants PSG are the only two sides to claim five wins from the opening five matches in the group phase, Messi – the recipient of a fourth European Golden Shoe – will not discount Barcelona’s eternal rivals.

“City are one of the strongest teams at the moment, with PSG,” Messi told Marca.

“So far, they have been the two teams that have shown themselves to be favourites, but this is a tough and very long competition.

“I never rule out Madrid because although they are not having the results that everyone expects, I have no doubt that in the end they will be fighting for everything, as they do every year.”

The same logic applies to Bundesliga champions Bayern Munich, according to Messi.

“Bayern are another big team that will also be there at the end, but it’s true that today City and PSG are the best,” the five-time Ballon d’Or winner added.

Although the Champions League might be the ultimate goal, La Liga leaders Barca have more urgent matters this weekend.

They travel to face Valencia on Sunday, in La Liga’s top-of-the-table clash.