Marcos earned his first ATP-level victory on grass this year, defeating World No. 38 Lukas Rosol 6-3, 6-4 on Tuesday at the MercedesCup.
Marcos is competing in the ATP World Tour 250 event in Stuttgart for the first time. The tournament transitioned to grass courts this year after 37 years on clay. He fired 10 aces, won an impressive 88 per cent (31/35) first serve points and converted on four of seven break point chances en route to the first round win.
Marcos will next face top seed and former World No. 1 Rafael Nadal in a blockbuster battle. His lone victory against the Spaniard, in Cincinnati 2010, came during one of his greatest seasons on the ATP World Tour when he toppled two World No. 1s (also Roger Federer in Indian Wells).
Overall, Marcos will be facing a former top-ranked player for the 40th time in his career, having battled against eight different former World No. 1s. Nadal won their most recent meeting in Madrid four years ago and owns a 7-1 head-to-head advantage. Marcos will be seeking to reach his first ATP World Tour quarter-final on grass since 's-Hertogenbosch 2011.