Major League Soccer (MLS) is one of the fastest growing soccer leagues around the world. The league's quality and competitiveness has signifanctly increased in the past few years with the signing of several renowed players from Europe and South America.

There have been many international stars that have played in MLS, such as David Beckham, Zlatan Ibrahimovic, Thierry Henry, and Andrea Pirlo. However, they were all free transfers and it was not until recently that MLS clubs began to make big money transfers. 

Since 2014, many teams have opened their checkbooks to bring in valuable players that would improve the league instead of signing free agent big name superstars who may not be fully invested in MLS. It is important to point out that we only include transfers made before 2020. Here we list the 10 most expensive signings in MLS history.

10. Michael Bradley

His signing was seen as a revolution to the MLS transfer market. After playing several years abroad in countries such as Holand, Germany, England, and Italty, the U.S. international returned to North America to sign for Toronto FC in Janaury 2014. 

The Canadian side paid AS Roma a transfer fee of $8.2 million and he has proven to be an instrumental part in the team's success over the years. Since arriving, he has helped Toronto FC reach three MLS Cup Finals, winning the championship in 2017 against the Seattle Sounders. 

9Miguel Almirón

The paraguan international was a key player for Club Atlético Lanús in 2016 when the team won the Argentine championship. In January 2017, Atlanta United announced the signing of Almirón for a transfer fee of $8.5 million. His spead and ball skills were a problem for opposing teams as he helped the club win their first ever MLS title in 2018, beating the Portland Timbers 2-0. After two years in Atlanta, his talents caught the eye of Premier League side, Newcastle United, who signed him for $26.4 million. A great piece of business for Atlanta United. 

8. Alexandru Mitrita   

The Romanian international caught the attention of New York City FC after a successful stint in his native country with Universitatea Craiova. In February 2019, the New York based club announced the signing of Mitrita for a fee close to $9 million. It took him very little time to win a spot in the starting 11, helping the team to finish first in the Eastern Conference with an 18-6-10 record.    

7. Matías Pellegrini

A product of the Estudiantes de La Plata youth system, he played only a handful games before catching the attention of Inter Miami. David Beckham's new MLS franchise, with was set to start playing in 2020, wasted no time in signing the young Argentine midfielder. 

The club paid a fee of $9 million and loaned him back to Estudiantes de La Plata for the remainder of the 2019 season. In January 2020, he returned to the club for the start of the preseason and has played in both of Inter Miami's first two games of the 2020 season. 

6. Brian Fernández

The Argentine goal scorer signed for Liga MX's side Necaxa in July 2018 and was one of the league's top scorers in the short time he spent in Mexico. His goal scoring ability caught the attention of the Portland Timbers, who signed him for a transfer fee close to 10.3 million in May 2019. 

He scored 15 goals in 23 games for the Timbers, but issues arrose in October 2019 when he voluntarily checked into MLS substance abuse program following years of substance abuse. Weeks later, the Timbers terminated Fernández's contract. 

5. Alejandro Pozuelo

A product of the Real Betis youth system, the Sevilla born midfielder was a journey man as he played for several club across Europe. After playing four seasons in Belgium for Genk, Toronto FC signed him for $10.3 million in March 2019.

Pozuelo was a vital player for Toranto in 2019, scoring 12 goals and helping the Canadian side reach the MLS Cup Final where they lost to the Seattle Sounders. 

4. Alan Pulido

The Mexican striker was one of Chivas' best players, scoring 12 goals in 18 games in the 2019 Clausura Tournament. He was also instrumental in helping the team win the CONCACAF Champions League in 2018. 

Sporting Kansas City were looking to strengthen their attack and saw him as a great fit for their team. Once the season in Mexico was completed, the MLS side paid a club record fee $9.5 million to sign Pulido.

3. Brian Rodríguez

The Uruguan winger made his debut for Peñarol in March 2018 and eventually became a regular in the starting 11. His talent quickly stood out and it did not take long for MLS teams to be interested. 

Los Angeles FC was the most interested and began negotiating to bring the young winger. More than a year after making his debut, Rodríguez was transferred to LAFC in August 2019 for a fee of $11.5 million. 

2. Ezequiel Barco

One of Argentina's most promising talents in recent years. At only 18-years-old, he was one of Independiente de Argentina's best players during the teams triumphen run in the 2017 Copa Sudamericana. He even took and scored a penalty that tied and eventually won the trophy for independiente as they beat Brazilian side Flamengo in the famous Maracaná stadium. 

It didn't take long for him to attract interest from foreign clubs. It was even reported that Portuguese side, Benfica, were interested in signing the young midfielder. However, it would be Atlanta United, who had just finished playing their first season in MLS, that would win his signature. The club was able to convince him that Atlanta was the right choice and they completed his signing for a fee close to $14.6 million in January 2018. In his first season, he was a fundamental part in the team's way of play and helped the franchise win their first ever MLS Cup title, beat the Portland Timbers 2-0.

1. Gonzalo Martínez  

The man nicknamed "El Pity" was one of River Plate's best players as they won the Copa Libertadores title in 2018. In fact, he scored the third goal to seal the victory in the final against arch rivals Boca Juniors at the Santiago Bernabeu in Madrid.

His performances attracted interested from several teams, but it was Atlanta United that beat everyone to the punch. In January 2019, the club announced the signing of the Argentine playmaker for $15 million, becoming the most expensive transfer in MLS history.