Private Phelan was a Terran Confederacy marine who fought during the Guild Wars. Phelan graduated from marine training at Turaxis Prime and was assigned to the Thundering Third unit. Its members were transported to Boro Airbase and then by truck with Fort Howe being the intended destination. However, the trucks came under attack by Kel-Morian Hellhounds, and while the marines escaped with minimal casualties, they were left with a shortage of transport. Under the leadership of Jim Raynor, two squads of marines had to hike by foot to Firebase Zulu, Phelan among them, bringing up the rear of the column.