Marrero earned his first world ranking late in 2000 as a 20-year-old, but he spent only a few weeks inside the top-500 until early 2005.

The very next week he gained revenge over Ramirez-Hidalgo to qualify into an ATP stop in Chile, where he again beat García before losing to No.

5 in doubles on 11 November 2013 after winning the ATP World Tour Finals with Fernando Verdasco defeating the Bryan brothers.

In January 2016, Marrero was featured in a New York Times article about his suspected match-fixing at the Australian Open.

[1] He announced his retirement at the 2022 Barcelona Open Banc Sabadell,[2] but continued to play on the ITF and Challenger circuits.