The Ronins made it to the second round of the competition after Prachuap FC forfeited in the lead-up to the first round match back in early March.
Assumption United currently play in the Regional League Division 2 in the Bangkok area and play their home mathces at the 15,000-seat SCG Stadium in Nonthaburi.
The Thai FA Cup is open to teams from all levels of Thai football. The second round slate of matches includes 18 teams from the Thai Premier League, 13 from Yamaha League-1 (Division 1) and 21 from Regional League Division 2 and 3.
Last year, Phuket FC lost in the second round of the Thai FA Cup in a 4-3 goalfest against an Ayutthaya FC team that played the most of the match with 10-men at Surakul Stadium.
The Ronins will look to improve upon their 2014 finish and move to the third round of the competition, which is scheduled to take place on July 8.