Marcos is set to begin his Irving Tennis Classic campaign against Dustin Brown in Tuesday's night session.
Marcos will seek his third victory over his German opponent, after earning a three-set win on the clay of Munich in 2012 and a tight four-set win on the grass of Wimbledon last year.
Marcos returns to the ATP Challenger Tour having found great success on the circuit in the past year. A finalist in Happy Valley to open the 2015 season, he compiled a 22-2 record in '14 and claimed four titles (Nottingham, Vancouver, Aptos and Geneva).
The seventh seed this week in Irving, which boasts one of the most elite fields on the ATP Challenger Tour, Marcos is in the same quarter of the draw as rising Austrian star Dominic Thiem and could face top seed Jeremy Chardy in the semi-finals. He opens play against Brown not before 7:00pm local time Tuesday.
