Marcos Alonso Mendoza is a Spanish footballer who has played for several prestigious clubs, including Chelsea FC, Real Madrid, and ACF Fiorentina. Marcos, who was born into a footballing family, began his career with 'Real Madrid' before moving on to the famous English team 'Chelsea.' On February 22, 2008, he was initially spotted while playing for Real Madrid B, the club's reserve team. He remained with 'Real Madrid' until 2010 when he was signed by 'Bolton Wanderers'. In August 2010, he made his first appearance for 'Bolton Wanderers' against 'Southampton FC'. He signed a three-year contract with 'Fiorentina' in Italy in 2013. In 2016, he signed a five-year contract with 'Chelsea FC' worth £24 million. He was arrested in 2011 after crashing his automobile into a wall and murdering a young woman. When the collision occurred, he was alleged to be driving under the influence. He was sentenced to 21 months in prison at first but was afterward punished with a large fine. He was also given a three-year and four-month driving suspension.

Marcos was born in Madrid, Spain, on December 28, 1990. Marcos Alonso Imaz, his grandpa, played for 'Real Madrid' for eight years, and Marcos Alonso Pena, his father, played for famous Spanish football clubs such as 'FC Barcelona' and 'Atletico Madrid.'

Marcos was born into a footballing family, thus it was natural for him to follow in his grandfather and father's footsteps. At an early age, he joined the 'Real Madrid' junior football team and began practicing with them before beginning his senior career with the same club.

On February 22, 2008, while playing for 'Real Madrid B,' he was spotted for the first time. However, he was unable to score throughout the game, and his club ultimately lost to 'AD Alcorcon.' He was allowed to participate in a 'La Liga' match for 'Valencia CF' on December 11, 2009.

On April 4, 2010, he made his professional debut as a substitute for Gonzalo Higuain, although he couldn't fully showcase his abilities because he came on in the 90th minute of the game.

The English team 'Bolton Wanderers' signed him on July 27, 2010. On August 24, he made his debut for the club, helping the squad to a 1-0 victory over 'Southampton FC.'

He made his league debut against 'Liverpool' on January 1, 2011. He made his debut for 'Bolton Wanderers' on March 31, 2012, scoring his first goal in a 3-2 win over 'Wolverhampton Wanderers.'

He left 'Bolton Wanderers' after three years to join 'ACF Fiorentina.' The Italian football club signed him to a three-year contract in May 2013. Despite 'Bolton Wanderers' best efforts to keep him, he went ahead with the contract.

On December 30, 2013, it was reported that he would be loaned out to 'Sunderland AFC.' Marcos had already made nine appearances for 'ACF Fiorentina' by the time he played his debut match for 'Sunderland AFC.'

On January 7, 2014, he made his first appearance for 'Sunderland' against 'Manchester United.' He contributed to his team's 2-1 victory over one of the best football clubs in the world. He even received the 'Sky Sports 'Man of the Match' award.

He appeared in the last game of the 'League Cup' on March 2, 2014. He was unable to salvage his squad from a 1-3 defeat to 'Manchester City.' Following that, he began making regular appearances for the club and also contributed to the team's success as 'Sunderland' rose to become one of the world's top football clubs.

On March 19, 2015, he returned to 'ACF Fiorentina' and scored his first goal for the club against 'A.S. Roma'. His goal was vital in his team's 3-0 victory in the 'UEFA Europa League.' During a three-year contract with 'ACF Fiorentina,' he played in over 80 matches.

Marcos was offered a fantastic opportunity to play for 'Chelsea FC,' one of the best clubs in the world when his contract expired. On August 30, 2016, he signed a five-year contract with 'Chelsea FC worth £24 million.

He relocated to England and made his 'Chelsea' debut in the 'EFL Cup' on September 20, 2016. His first match for the club went well for him, as he played the full game and helped the squad to a 4-2 victory over 'Leicester City.' His squad was defeated by 'Arsenal' in their following match, losing 0-3 to them.

Marcos scored his first goal for 'Chelsea' against 'Everton FC' at Stamford Bridge on November 5, 2016. He scored two more goals in a 3-0 win over 'Leicester' at the 'King Power Stadium on January 14, 2017.

His name was selected in the Spanish national squad for exhibition matches against Germany and Argentina as a result of his outstanding performances.