With David Moyes leaving to join Everton and Craig Brown entering the managerial fray at Deepdale, Lonergan remained optimistic about his future at the club; indeed, he was promoted to the first-team squad for the final stage of the 2002–03 season as an understudy to Scotland international Jonathan Gould. With Gould out injured for a period of the following season, Lonergan snapped up his goalkeeping gloves and stood between the sticks for the first time in the league against West Brom, two years after his debut. Gould fell out of favour soon after, and Lonergan remained as the first choice until the end of that season. But this was short–lived when Lonergan lost his first team place after breaking his hand, resulting in him being out for six weeks and missing out for the rest of the season. After returning to training in the pre–season, Lonergan returned to the first team as first choice goalkeeper and on 2 October 2004 Lonergan scored a goal from his own penalty area in the 39th minute against Leicester City to equalise, after his long kick bounced over Leicester goalkeeper Kevin Pressman after defender Matt Heath had let the ball bounce. The game ended in a 1–1 draw. He remained at Deepdale for the 2004–05 season under the watchful eye of new manager Billy Davies, and played a part in 65% of the season before he ruptured his cruciate ligaments before a game against Ipswich Town, due to Lonergan's injury, Carlo Nash was signed as a replacement by Billy Davies from Middlesbrough to shore up the goalkeeping crisis. It wasn't the first time Lonergan suffered an injury: he broke his hand during training.