ESSENDON has lost two more players to injury, with speedster Courtenay Dempsey and highly rated key-position prospect Scott Gumbleton again sidelined as both prepared to make their returns from hamstring injuries.

But with 14 players sidelined this week due to injury or illness, opportunities presented for first-round draft pick David Myers, father-son recruit Darcy Daniher and mature-age rookie Jarrod Atkinson, who are all set to make their debuts against Port Adelaide at Telstra Dome on Sunday, and Tom Bellchambers, who has been named in the squad.

The Bombers will be without Dempsey for another six to eight weeks after the young Queenslander was found to have stress fractures in his right leg, while Gumbleton strained the medial ligament in his left knee at training yesterday and is likely to be out for up to a month.

Dempsey had already spent four weeks on the sidelines with a hamstring strain — after managing only one game last season also because of hamstring problems — and was ready to make his return when the latest injury was discovered, team manager David Calthorpe said yesterday. "He was going to play last week, but he was shin sore, so it's disappointing," Calthorpe said.

Coach Matthew Knights said it was a big blow for the running half-back, who had shown excellent form in the pre-season and had looked a strong chance to make a real impact .

"It's extremely frustrating for Courtenay. His form was starting to pick up, and he was getting opportunities, and to get struck down like that is really difficult," he said.

Knights said the club was still confident that Dempsey, who only started playing Australian football aged 12, would be an important part of its future, adding: "We think Courtenay has got the game to be a big-time player. Our mind hasn't changed on that."

Gumbleton has also had problems with hamstrings, but looked set to make his return until yesterday's hiccup.

Calthorpe described Atkinson, who was made a rookie after playing under Knights at Bombers VFL affiliate Bendigo over the past two years, as "a well-built 23-year-old". "He's got a lot of upper-body strength, he's got leg speed, he can catch the ball overhead. We hope he's going to develop into an exciting running player who can break the lines for us."