Jackson in line for Ulster debut
Fly-half Jackson, 19, was named on the bench for the game at Parc y Scarlets, but although Ian Humphreys was originally selected at half-back, there is still a major doubt over his recovery from a wrenched shoulder sustained in the defeat by the Ospreys last week.
Jackson, a product of the Methodist College rugby nursery, has been a key member of the Ireland U20 Six Nations side and his promotion would be a major step-up in class.