The Windies are also missing flamboyant big-hitter Chris Gayle, who complains of injury problems and makes only sporadic appearances for his country.
Gayle also missed the West Indies' one-run Twenty20 win over India in Florida last month, while Russell will front a hearing into claims he missed three drugs tests in a 12-month period, an offence which could trigger a two-year ban.
Brathwaite will now captain the side in UAE while towering former fast bowler Joel 'Big Bird' Garner replaces Simmons, who repeatedly clashed with the West Indies board.
Brathwaite hopes his team will show their huge talent in the humid conditions in the United Arab Emirates, where they also trained ahead of the World Twenty20 in India.
"It wasn't as hot early in the year, but, apparently, we're smack dab in the middle of their summer, so it can get very, very hot," said Brathwaite.
"It's for the players to prepare well, manage themselves well off the field, rehydration-wise, get enough rest, and each and every one of us is a professional, and evidently performing well when the games come."
Brathwaite's uncapped players -- including wicketkeeper-batsman Nicholas Pooran, all-rounder Rovman Powell and fast bowler Kesrick Williams -- will also want to fire against a dangerous Pakistan side.
Pakistan are also in good form, smashing hosts England by nine wickets in the only Twenty20 game of their tour in what was Sarfraz Ahmed's first match as skipper.
Ahmed, who replaced Shahid Afridi following Pakistan's first-round exit in the World Twenty20, hopes his team won't be overawed by the champions.
"We didn't think England were World Twenty20 finalists when we beat them at Manchester," said Ahmed.
"We will do the same here, go out and play hard because the team which plays well on the ground wins a T20 match."
He added: "Even without Gayle and Russell, West Indies is strong and a T20 match is not won with big names only."
Middle-order batsman Umar Akmal will be in focus after being recalled following his axing on the England tour over disciplinary issues. Umar smashed a fiery century in a national Twenty20 event to force his comeback.
The second match will follow at the same venue on Saturday with the third in Abu Dhabi on Tuesday. The teams will also play three one-day internationals and three Tests.