​After leaving FC Barcelona, Robert Lewandowski has officially begun the next chapter of his career with MLS club Chicago Fire.The 37-year-old striker arrived in Chicago on Monday evening and took part in his first training session with Chicago Fire on Tuesday, receiving a warm welcome from both his new teammates and coaching staff.AdvertisementAdvertisementAdvertisementHead coach Gregg Berhalter greeted the Polish forward at the club’s training facility before Lewandowski joined the squad for his first workout as a Fire player.Speaking at his introductory press conference, Lewandowski admitted that walking away from Barcelona was one of the toughest decisions of his career.“I didn’t want to play for any other team in Europe than Barcelona. I couldn’t imagine it,” Lewandowski admitted, as quoted by Mundo Deportivo.“It was a difficult decision for me and my family, but I’m very happy to join this team. I want to win trophies in this new stage of my career and my life,” he added.AdvertisementAdvertisementAdvertisementThe striker also joked about adapting to life in the United States, saying:“After living in Barcelona, it’s not easy, but I’m from Poland, so I’ll adapt.”Lewandowski leaves Barcelona after four successful seasons, during which he established himself as one of the club’s key figures and continued adding to his remarkable goalscoring record.Despite having been at the club for only four years, the 37-year-old veteran departed the club as a legend, having helped Barça win three La Liga titles and several other domestic honours.The striker had interest from clubs in Turkey, while AC Milan in Italy were also keen, but he opted not to continue in Europe after bringing an end to his time in Catalonia.Lewandowski left Barcelona after four successful seasons. (Photo by Aitor Alcalde/Getty Images)AdvertisementAdvertisementAdvertisementNow under contract with Chicago Fire until 2028, the veteran forward is aiming to make the same impact in Major League Soccer and help guide the club back to domestic success as he embarks on a fresh challenge in the final stage of his illustrious career.Following the break for the World Cup, the MLS season resumes this week, with Chicago Fire set to host the Vancouver Whitecaps in the early hours of Friday morning.The match could provide an immediate reunion between Lewandowski and former Bayern Munich teammate Thomas Müller, who now plays for the Canadian club.Whether the Polish striker makes his debut remains uncertain, as he will have completed only two training sessions before the fixture. Even if he does not feature, he is expected to be presented to supporters at Soldier Field ahead of the match.