Sergio Aguero needed Lionel Messi to tell him why he was being continually overlooked for Ballon d'Or honours.

Despite scoring a record 260 goals for Manchester City, Argentine striker Aguero has never come close to winning the trophy that Messi has carried off six times.

Being repeatedly overlooked began to trouble Aguero, but when Messi spelled out what he was lacking, it all made sense.

Now at Barcelona, Aguero looks back on his City career and appreciates why his feats fell short of making him a major contender for a prize Messi has won more than anyone else.

"Many times I thought about what was missing," Aguero told Spanish newspaper El Pais. "And one day I asked Leo. He told me that to have a chance to win the Ballon d'Or I had to win the Champions League. And he is right.

"The subject of trophies with the national teams is also important. Take [Fabio] Cannavaro's case, for example, when he won the World Cup in 2006."

Cannavaro took home the Ballon d'Or that year, with Italy team-mate Gianluigi Buffon in second place.

"I played great seasons, scored many goals and won many titles," Aguero said, "but I was not in the Champions League final. And last year when we reached the final, I had a knee problem, COVID and different injuries."

In 10 years at City, Aguero hit at least 20 Premier League goals in a season on six occasions, and only in one campaign (2012-13) did his minutes-per-goal record in the competition creep above one goal every 140 minutes.

That is a record that attracted Barcelona, with Messi's run of form over the same period having seen him score at between one every 57 minutes (2012-13) and one every 143.1 minutes (2006-07) in LaLiga.

Aguero has recovered from a calf injury and on Wednesday he featured in a training game for Barcelona against UE Cornella, meaning a competitive debut could be just around the corner.

It remains to be seen whether Aguero will be fit enough to play a part in Sunday's LaLiga match against Valencia, as Barca look to get their season on track.

A home fixture follows against Dynamo Kiev in the Champions League; then comes the first Clasico of the season, with Real Madrid visiting Camp Nou on October 24.

Long-time Argentina team-mate Messi was at Barcelona when Aguero arrived, but he has since departed for Paris Saint-Germain.

Aguero recalled visiting Messi when it emerged he would be forced to leave Barcelona.

"It was a moment of shock. He was in a very bad way. When I found out I couldn't believe it. That Saturday I went to see him at his house," Aguero explained.

Aguero said he attempted to cheer up Barcelona's record goalscorer.

Now there will be expectations on Aguero's shoulders, and despite losing Messi, he says moving to Barcelona was the right choice once his City contract expired.

"Let's be honest. What player does not want to be at Barca?" Aguero continued.

"The majority of footballers would like to wear this shirt, no matter how good or bad Barca is. I arrived with the expectation of playing with Leo and that a good team would be put together, which was what the club tried to do. When they called me, I thought: 'I don't care what they pay me. I'm feeling good and I'm going to help the team as much as I can.'"