Why leave Liga MX for MLS and vice versa? Money, quality of life and level of competition

"The adaptation aspect, the way they acclimate is really not that difficult because they are already in the region playing in CONCACAF, playing in difficult environments, climate, altitude, all those things. ... And then there's also travel that goes along with it," Vermes explained to ESPN.

European players can sometimes struggle with such issues. Columbus Crew president Tim Bezbatchenko agrees with the compatibility of Liga MX players to MLS and the fact that the Hispanic population in many of MLS cities -- as well as inside the clubs themselves -- can make settling easier. The profile of Liga MX players coming from the most popular league in the U.S. in terms of television viewership also doesn't do any harm for marketing purposes, especially in areas with a large Hispanic population.

Clearly, the most important aspect is their fit on the field. One of the most difficult tasks in international scouting is translating a player's qualities from one team and league and projecting how they would fit into your coach's ideas in a new league. But the geographic accessibility of Liga MX and increased play between the two leagues through Leagues Cup and CONCACAF Champions League allows clubs to scout players facing their domestic rivals, or even directly against them, with ease.

"The fact our leagues are playing each other in real competition, you get to evaluate and compare the talent like for like, on the same pitch at the same time, which is something that you don't get to do in other countries in South America," Bezbatchenko said.

The financial reality

Quality of life, proximity and an improving on-field product are important, but wages have arguably the most profound influence over player movement in world soccer. Players generally move where they can get the most money. The likes of Pulido, Flores and Zelarayan are unlikely to have swapped leagues for a pay cut. The reality is that the vast majority of transfers north from Liga MX have been on designated player (DP) contracts, while the increase in targeted allocation money (TAM) was key in bringing in Corona, Alanis, Carlos Fierro (Cruz Azul to San Jose Earthquakes) and Felipe Mora (Pumas to Portland Timbers).

"I don't think it's a coincidence that TAM [increased] in 2018 and now you've seen an uptick in clubs' activity in the market," said Dimitrios Efstathiou, senior vice president of MLS player relations and competition. But overall, Liga MX still has superior spending power at the midtier level of the roster.

The average MLS wage in 2019, excluding designated players, was $345,867 (before tax), up from $138,140 in 2014, according to the MLS Players Association. It's a significant increase and clearly gives more room to maneuver on the world market, but as things stand, wages in Liga MX are 20 to 30 percent higher than in MLS (again, excluding DPs), according to sources' estimates. Higher bonus payments in Liga MX and often cheaper cost of living in Mexico also need to be factored in.

However, financial realities are not monolithic in either league and the negotiations between the MLSPA and MLS over the next collective bargaining agreement -- their deal is set to expire this Friday, with negotiations ongoing -- could shift the dynamic could again.

In Liga MX, where there is no salary cap, and there's an increasing polarization between the haves and have-nots, with Tigres, Monterrey, Cruz Azul, America and Chivas the economic powerhouses. Sources indicated that at least seven players at Tigres make more than $1 million a year, with French striker Andre-Pierre Gignac reportedly earning four times that number. It's impossible for any club in MLS to match that spending on squad depth.

Other Liga MX clubs are employing more rational models of player recruitment that seek to balance the budget -- or even make a significant profit, like Necaxa has in recent windows -- while trying to compete with the powerhouses. And those clubs are often more willing to negotiate with MLS clubs than fellow rivals, primarily because MLS clubs tend to pay punctually, in fewer installments spread over a shorter period, which isn't always the case in Mexico.

Wages in Mexico are also changing. The end of the owners' informal and unwritten pacto de caballeros (gentlemen's pact) -- which prohibited free movement of players domestically when their contracts were up -- in 2018 has created free agency. The full effects of that are still in flux, but many Liga MX clubs are less willing to splash out on bumper contracts without the safety net of recouping a transfer fee at the end of it, according to sources.

For players moving south, it's all about quality

Liga MX maintains its own competitive advantage over MLS in attracting those players who fall below the designated player bracket, such as Saucedo, Yoshimar Yotun and Rafael Baca, who all earn more in Mexico than they did in MLS.

For Acosta, a move to Paris Saint-Germain in January 2019 came agonizingly close until D.C. United and the French giant failed to agree terms. One year later, he's at Atlas. His contract with D.C. ran down and he was, in part, persuaded to join the Guadalajara club by manager and fellow Argentine Leandro Cufre.

"I've wanted to play in Mexico for a long time," Acosta told ESPN, and added that he had options elsewhere. "The quality of football is high."

Atlas president Pedro Portilla says the issue of security in Mexico is sometimes mentioned when the club negotiates with foreigner players, but that the lifestyle in Guadalajara in particular can actually attract players.

"It has happened that foreign players have asked us about those things before taking the decision," Portilla told ESPN. "The truth is that the best answer we can give is the number of foreigners that come into Mexican football, and that once their careers are over, they often choose Guadalajara as the place they want to keep on living and to raise their kids."

For recent Pumas signing Saucedo, the gap in quality was important. MLS is improving, but Liga MX clubs have won the past 14 editions of the CONCACAF Champions League. In no confederation is one country so dominant at club level as Mexico is in CONCACAF.

"The difference is quite big," said Saucedo, who previously played at Veracruz, on his presentation with the media earlier in January. "There's isn't as much pressure in MLS as there is here. When you come to a big club they talk a lot about the playoffs and having to be in there. In MLS, in the team I was at, if we got into the playoffs, great, and if not, nothing happens."

Saucedo believes his chances of making the U.S. national team will be boosted by playing in Mexico.

The opinions of Saucedo, Pulido and others in explaining the factors pushing and pulling players between Liga MX and MLS are often divergent, but it is hard to find a single voice to dispel the notion that increased movement between these two leagues will continue into the summer and beyond.