England internationals Steve Borthwick and Richard Wigglesworth and Scotland forward Kelly Brown all come into the side.
Gloucester have also made three changes for the clash - with Freddie Burns, Tim Molenaar and Jim Hamilton handed places in the starting XV.
And with Saracens the favourites after 11 straight wins - including a victory over the Cherry and Whites - coach Bryan Redpath knows his side will have to raise their game once again.
"Sunday is huge for us," he said. "We're aware of that and we've achieved some good things this season. But we want to improve upon the performance down there of three weeks ago.
"We were disappointing that day. Credit to Saracens, they're very efficient and a very workmanlike side. They get some stick but they work hard for each other so we have to fight in every aspect of the game."
Sarries boss McCall said: "Gloucester are a very good side but the result of the game at Vicarage Road last month is irrelevant. We know that we will be facing a very different opponent, but it's a challenge we are looking forward to and we can't wait to get out on the pitch."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The Barbarians are one of the top invitational rugby sides with a long history and classic rugby jersey.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Lions get ready for their matches with this green training jersey. It's what the players wear. Get in the Gear!
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
$29.99
The Lions are ready to get their Australia tour underway. They arrive in Perth on Monday.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.