The return of Essendon key forward Scott Gumbleton has been delayed by at least a week with the injury-prone 21-year-old to miss Friday's NAB Cup opener against West Coast at Subiaco.

Gumbleton's career has been cruelled by injury and he has played just five games since being selected at pick No.2 in the 2006 AFL draft. While he has had a strong pre-season, a back spasm at training on Monday has seen the Bombers take a safety-first approach with him.

"Scott Gumbleton unfortunately had a slight back spasm yesterday in a light hit-out so won't be making the trip to Subiaco," coach Matthew Knights told reporters on Tuesday.

"He (Gumbleton) was pretty locked up yesterday but was out there this morning (Tuesday) walking better and the medical staff put some work through him and he had a smile on his face this morning so we are aiming for the second round."

Knights said Gumbleton had shown plenty of positives in an intra-club match and he was confident that 2010 would be the year that he would start to develop the potential he has.

"It was very pleasing and fantastic to see him run around last week in Shepparton," he said.

"He played four, 20-minute quarters and he pulled up well and just in an innocuous incident yesterday (at training) he slightly twisted and locked up his back."

However, Bombers fans will get to see three of the club's highest-profile recruits on Friday night with Jake Melksham, Michael Still and former Hawk Mark Williams all set to make their debut for the club at Subiaco.

"We're really excited about Jake Melksham, our first pick in the National Draft (No.10 overall), playing on Friday night," Knights said.

"Michael Still was taken as a 17-year-old at the end of 2008 and did Year 12 studies last year while at the club so he is the still the same age as our first-year players."

Williams attracts most interest having played 111 games for Hawthorn before arriving at the club during trade week.

"Mark has done an enormous amount of work with his fitness in the last two months," Knights said.

"We'll be looking to him to kick goals and set up some others."

Knights confirmed that Michael Hurley, currently on assault charges after an off-season incident involving a taxi driver, will be under consideration for the Eagles game.