Simmons steps in to lead Reds
It will be Simmons' first time captaining Queensland, but he has spent the last 12 months in a senior leadership role after being named vice-captain of the side last year.
Slipper will resume his role as captain upon return from injury.
Simmons and Slipper are two of the more experienced members of the Reds squad, with a combined total of 171 caps for Queensland and 134 Tests for Australia. Both players were part of Australia's World Cup campaign, where the Wallabies finished second.
Simmons said he was thankful for the opportunity to lead his state, but that his focus was on the team, not individual honours.
"It's an honour and a proud moment in my life. I'm grateful for the opportunity, but James is still our captain and I know he'll be offering the team plenty of leadership and support from the sidelines," he said.
"It's not really about me, or James, it's about the team and what we want to build here and that's something everyone is contributing to."
Slipper said Simmons would do a tremendous job as stand-in skipper.
"It's obviously disappointing that I won't be out there at the start of the season, but not only myself but the whole team has a lot of confidence in Rob, he’s been at the Reds a long time and he has a genuine love for Queensland," said Slipper.
"He's a well-grounded person and he knows the game well, it's a great opportunity for him and right reward for the hard work he puts in on and off field."
Reds head coach Richard Graham said it was important for the team to have continuity in its leadership and that Slipper and Simmons were highly regarded by their teammates.
"James and Rob are two of our more experienced players, they're respected by their peers and are incredibly passionate and committed to the Queensland cause," he said.
"They've both experienced leadership roles here at the Reds and also at the Wallabies in the last 12 months, with James part of the formal leadership group at the World Cup and Rob leading the line-out.”
The Reds' will host two pre-season matches at Ballymore Stadium against the Crusaders on Saturday, February 6 and the Brumbies on Friday, February 12.
Their first match of the 2016 Super Rugby season is against the Waratahs in Sydney on Saturday, February 27.
