Lionel Messi's Barcelona were beaten at Manchester City

Pep Guardiola says it is "impossible" Mikel Arteta was at the centre of an alleged tunnel row with Lionel Messi on Tuesday.

Spanish press reported this week that Messi reacted to an insult hurled by an unnamed Manchester City player in the aftermath of Barcelona's Champions League defeat at the Etihad.

Fernandinho and Messi's friend Sergio Aguero both denied any role, and Guardiola's assistant Arteta was later named as the City man involved.

But speaking at his pre-match press conference ahead of Saturday's game against Middlesbrough, Guardiola said, "I spoke to Arteta - it's impossible that incident happened. He admires Messi and Barcelona a lot."

Arteta came through the La Masia academy as a youngster, and another former Barca man will be in goal for the opposition on Saturday as Victor Valdes lines up for Boro.

Watch highlights of Manchester City's 4-0 win away at West Brom Watch highlights of Manchester City's 4-0 win away at West Brom

Valdes' haul of trophies under Guardiola included two Champions League and three Liga titles.

"He is one of the best goalkeepers," Guardiola said. "The success at Barcelona would not have happened without him. I am very happy for him."

Boro make the trip on the back of an upturn in form following a goalless draw at Arsenal and a home defeat of Bournemouth, and ex-City striker Alvaro Negredo could start.

"I know how good [Negredo] was here," Guardiola said. "After injury he had a few problems. I saw Middlesbrough against Arsenal and was really impressed."

As for City's personnel, Bacary Sagna and Fabian Delph are still out but Vincent Kompany is in contention after successive games on the bench.

Mikel Arteta (centre) came through the ranks at Barcelona

"I still have to think about my team, speak a little bit with the physios," Guardiola said. "The Barcelona game was always tough mentally and physically, but of course [Kompany] has a chance."