Silverwood, 27, who has taken only 11 wickets in five Tests at an average of 37.72, flew into Hobart on Tuesday.
"This is a fantastic opportunity for me to cement a place in the Test side," Silverwood told a news conference.
"If the opportunity comes, I'll grab it with both hands."
England added Silverwood and Surrey paceman Alex Tudor to their squad last week as replacements for Simon Jones and Darren Gough.
Jones was ruled out of the series after injuring his knee during the first Test in Brisbane while Gough was sent home without bowling a ball because of a long-standing knee injury.
Tudor echoed Silverwood's pledge, saying he feels in better shape than ever as he attempts to force his way into the England side.
"I've been working on my action a little and the basic fitness work we have done has been good because I feel a lot fitter now," said Tudor.
"We had four weights sessions a week and if you don't improve with that sort of schedule then you're struggling and I was happy with the way I went about my training.
Tudor's nine-Test career has been plagued by accusations that he lacks the stamina to succeed at the highest level - claims he is keen to disprove over the next two months.
"During the season I only missed two weeks because of my shins," he added.
"I bowled my overs for Surrey and for England so I don't know where this stuff about me not having any stamina came from.
"Anyone can improve on their fitness and I'm no different, but at times it's difficult to take criticism like that."
Queensland batsman Jimmy Maher will captain Australia A in a three-day match against England starting in Hobart on Friday.
England go into the match without captain Nasser Hussain, who will fly to Perth during the weekend to join his pregnant wife Karen.
She is due to give birth to the couple's second child next week.
Steve Harmison (shin splints) and Andrew Flintoff (hernia) are expected to be fit for selection against Australia A alongside Tudor and Silverwood.