Rafa Marquez has retired but will he still play for Mexico at the World Cup?

Rafa Marquez's club career has come to an end. The most decorated player in the history of Mexican football bowed out as Atlas drew 0-0 against Pachuca on Saturday in Estadio Hidalgo.

There should be no doubt as to how important Marquez is to the Mexican game. Only Hugo Sanchez has come close to Marquez's haul of four La Liga titles, two Champions Leagues, two Liga MX titles and one Ligue 1 trophy.

Whether 39-year-old Rafa Marquez plays another competitive game of football again or is definitively retired as a player will now depend on his name being on the list to represent Mexico at Russia 2018. A recent ESPN report suggested that Marquez has been given the green light to feature, following a spell out of the national team after the former Barcelona defender was accused by the U.S. Treasury Department of having links to a drug trafficking organization last August. But as yet, there has been nothing official.

If the legal path is clear for Marquez to play in Russia, the decision of whether the "Kaiser of Michoacan" will be given the chance to appear at his fifth World Cup, and perhaps become the first player to captain a side at five separate tournaments, will be on coach Juan Carlos Osorio's shoulders.

Osorio has praised Marquez during his reign as El Tri coach while maintaining that Mexico has to learn to play without him. But if it is Osorio's call, Marquez's chances of making history appear high.

The experience and leadership Marquez brings is obvious, but less known is his crucial role after the 7-0 loss to Chile back in the quarterfinal of the 2016 Copa America Centenario -- an event that rocked Mexican football and represented a crucial moment in Osorio's reign. It came at a time when hope was high: El Tri had won nine and drawn one of Osorio's first 10 games in charge, conceding only two goals.

For Osorio, the loss was difficult to take. He'd never experienced anything like it in his career and afterwards, he met with Marcelo Bielsa and others who had gone through a similar disappointment in their career as he sought to understand and get over the devastating defeat.

"It was a huge moment," said Osorio in a recent interview with ESPN FC. "When I look back, I can tell you honestly that the game in which I have learned the most."

But the loss against Chile was notable because it drew a line in the sand. Would the federation let Osorio go? And did the respect between the manager and the squad evaporate after such a high-profile loss? That's where Marquez's role as a leader in the dressing room becomes clearer, and helps to further explain why Osorio is arguably keen to include him in the squad for Russia.

"After the game, I went into the locker room and I wet my face and head," recounted Osorio in a recent interview with ESPN FC, in English. "I was getting ready to go to the press conference and a lot of things were going through my head."

"I gathered the whole group and I remember I said, 'I'm going out. I'm going to take full responsibility for this defeat because I have enough character, enough courage, enough balls to say it was my responsibility."

"But if we lose the respect or our trust for what we are doing, I'll resign."

It was then that Marquez spoke up, according to Osorio.

"'On behalf of the boys, of the group, please stay because not only do we trust you, we believe in you, we respect you... so please do not resign, we want you to stay," was how Osorio remembered the statement.

Osorio's response was to tell Marquez and the players that if they did feel that way, they should relate the same message to the awaiting journalists, many of whom called for the Colombian to be dismissed.

"I did say if I ever lose your respect, your trust or your confidence in my ability in what we are trying to do, I will leave tomorrow," stated Osorio.

Marquez didn't play the game against Chile. His lack of involvement had caused something of a media stir in Mexico, because he'd traveled back to Guadalajara for the birth of his child and remaining on the bench. There were complaints from onlookers that discipline in the squad wasn't what it should be, and that Osorio was a soft touch. The way Marquez was captured giving instructions to players from the touchline was interpreted by some as the veteran stepping in for Osorio and challenging his authority. But after the game, Marquez came to Osorio's defense to publicly state he should stay.

"[The message is to keep] calm, keep heads cool and think things through properly," said Marquez. "This one result maybe doesn't change what we have been doing previously with Osorio. I'd give him the vote of confidence to keep working."

Team leaders like Javier "Chicharito" Hernandez, Hector Herrera and Guillermo Ochoa all followed his lead. Hernandez said the loss "hurt Mexico's soul" and apologized to the Mexican people.

"I remember we got in and there was total silence," said Santos Laguna defender Nestor Araujo in a recent interview with ESPN FC. "Then the coach came in and I think he felt ashamed, like us, about the result."

"Then Javier Hernandez and Rafa Marquez spoke, and spoke strongly. They said the responsibility was on the players on the pitch and not coach Osorio, and we shouldn't distance ourselves from responsibility."

"We had faith in the coach. We all felt bad and it still hurts today."

Since then, Mexico has played 34 games. Marquez has featured in nine of those, with his last back in the final game of El Tri's Confederations Cup campaign against Portugal.

Regarding his involvement, there are question marks on the playing side of the decision given that Marquez's athletic capabilities are diminished at his age, although no other player has definitely made the holding midfield position his own. Crucially, Osorio invited the former Monaco player to participate in the online platform that a group of 40 of Mexico's player pool have access to in order to prepare for Russia 2018.

"I think with Rafa, we'd have somebody who can distribute the ball really well," said Osorio last month. "That's something that we missed... with the national team. Now, we don't see him as a central defender anymore.

"We think because of pace and age, [Marquez] should be moving further up the pitch. But as a central midfielder and if he is in top form, I think it would be very difficult to leave him out."

Given Marquez's experience and how he has supported Osorio, one can expect the veteran to be in Russia with Mexico as long as there is no legal impediment.