Injuries had already ruled out full-back and leading points scorer Leigh Halfpenny as well as scrum-half Rhys Webb, with Liam Williams and Mike Phillips starting in place of them.
Gatland has also brought back Luke Charteris in place of Jake Ball while Ken Owens and Rhodri Jones start in the front row with Richard Hibbard and Adam Jones dropping to the bench.
At fly-half Dan Biggar gets the nod in place of Rhys Priestland and Gatland has called on his side to seize their chances against Scotland.
"Saturday is an opportunity for us to put in a performance we know we can and finish the Six Nations on a high," Gatland said. "We've made a number of changes and freshened things up with a just a six day turnaround between matches.
"Liam [Williams] and Mike [Phillips] come in with Leigh [Halfpenny] and Rhys [Webb] ruled out and Dan Biggar gets his opportunity at fly-half. In the front-row Ken Owens and Rhodri Jones get their chance to start after impressing off the bench and it's good to have Luke [Charteris] back from injury in the second-row.
"Scotland will come looking to play some rugby and had a morale boosting win against Italy and were unlucky to lose against France in recent weeks. We will be looking for a more accurate execution this week to finish with a win at home in Cardiff."