Ramsey's injury was sustained during the first half of the Dragons' win over the Manly Sea Eagles at Kogarah on Friday evening.
It was a victory which has kept the Dragons' finals hopes alive, with the club now just two points out of the top eight with six rounds to go, in what was a crucial clash against the understrength Sea Eagles who are also in a fight for their finals life.
Ramsey went down with a knee injury early in the game, and it has now been confirmed by the club that his scans have shown a Grade 2 medial ligament injury.
Immediate concerns were expressed for a more serious injury, so on one foot, the scans will actually come as good news for Ramsey, who has been electric at fullback since replacing Tyrell Sloan in the position. The club have confirmed he will miss "at least two weeks."
A tight contest which saw the up and coming Treigh Stewart score a hat-trick at fullback, Sullivan only lasted 19 minutes before being brought from the field.
The club have confirmed the fringe first-grader, who could have considered himself unlucky not to be included in the NRL side on Friday evening, has suffered an AC joint injury which will keep him out for "approximately two to three weeks."
The NSW Cup side currently sit four points inside the eight and will be relying on a timely return for Sullivan as they push for the finals after what was also a crucial win over the Knights, who are ninth.
In first grade, it's expected Tyrell Sloan will replace Ramsey in the coming weeks, although Moses Mbye moving to the back and Jack Bird to the centres with Moses Suli out until the finals is another option.
The Red V have a difficult next fortnight, playing the North Queensland Cowboys and Cronulla Sharks, before a run home which features the Canberra Raiders, Gold Coast Titans, Wests Tigers and Brisbane Broncos in the final four weeks.