The 29-year-old paceman is likely to share the new ball with the more livelier Mitchell Johnson on a dry Dubai stadium pitch which will have little to offer for the fast bowlers.
But Siddle said on Monday that getting ten wickets would be key.
“I think we need to get ten wickets, it does not matter which ones we get but there are a few older blokes in the middle – Younis and captain Misbah – they are going to be tough ones out there,” said Siddle.
“I think we always want to put pressure on the captain and they are the players we are looking obviously to get on top of and that will give confidence to everyone else as well.”
Pakistan’s fragile batting was exposed in the preceding 3-0 one-day series loss and will be under pressure as Misbah has been struggling with his batting form, having scored only 67 in his last four Test innings.
Siddle stressed that it would be important to use the new ball well on the Dubai pitch, known for helping the spinners more.
“I did not have a look at the wicket today and I think using the new ball well will be important and you need to get a few breakthroughs and obviously reverse swing and spin is going to play a part,” said Siddle.
Pakistan have not beaten Australia in a Test series since their 1-0 home win in 1994.
Australia have won 13 of the 14 Tests played between the two sides.
Siddle said Australia’s defeat in the four-day warm-up game against Pakistan ‘A’ stood for little.
“You never want to lose a match,” said Siddle of the 153-run defeat in Sharjah on Sunday.
“It was disappointing and it is sure we never want to lose any match, whether we are playing just a practice match, a first class standard or at Test match side.
“It was disappointing for the result but all in all we did get to play everyone in the squad and sometimes you don’t get that opportunity in a lot of tours.”
Siddle hinted that Australia might play two spinners in Nathan Lyon and Steve O’Keefe in the first Test.
Pakistan will also likely include uncapped leg-spinner Yasir Shah and left-armer Zulfiqar Babar in their starting eleven.
The second Test will be played in Dubai from October 30- AFP