KEY FORWARD prospect Lewis Johnston, the Sydney Swans' first-round pick in November's NAB AFL Draft, is not without a chance of making his debut this season.

Johnston, the seventh-youngest listed player on an AFL list in 2009, was earmarked for development in the Swans reserves this year.

But Swans reserves coach Brett Allison said the South Australian was a genuine chance to feature late in the season.

"If he can keep developing as he has the last month and his form stays as it has the past two weeks, it's not out of the realms of possibility that he plays in the back half of the year," he told sydneyswans.com.au.

Allison said the 18-year-old was the Swans' best player against Belconnen in last Sunday's first round of the AFL Canberra competition.

"He's shown already he can play. His ability and talent and his intensity in games has been really surprising," Allison said.

"We haven't seen that out of him on the tracking track, as he has been a little bit lackadaisical at times.

"His first eight weeks were a real learning process for him on the training track, but he's got on top of that in the last month."