England, who have not lost a Six Nations game since 2018, are seeking an eighth consecutive title and a fifth Grand Slam in a row.
Prior to the tournament, Mitchell lost four of his matchday squad from the World Cup final to pregnancies.
Three of those – Zoe Stratford, Abbie Ward and Rosie Galligan – have all played in the second row under Mitchell.
Lock Morwenna Talling was carted off on a stretcher against Ireland, with Mitchell confirming that she and replacement scrum-half Natasha Hunt will likely miss the rest of the tournament through injury.
Loughborough Lightning’s 19-year-old Haineala Lutui, who has mainly been deployed in the back row for her club, came off the bench to make her debut as Talling’s replacement.
“We must adapt, as we have lost four international locks – we will be a team of back rowers by the end of the tournament,” Mitchell said.
“If that is the way it is going to be, then so be it. There are different ways to play this game, and if that means using back rowers, then we will make it work.”
Megan Jones replaced Stratford as England captain and stepped up with a strong defensive performance, picking up the player of the match.
“There were always going to be nerves coming into this campaign off the back of an amazing World Cup, so there was always going to be that expectation,” Jones told BBC Sport.
“We want to play in front of big crowds like that, and sometimes the game can get stuck, but we found ways through, and that is what a winning team does.
“Some nerves, but we will brush up on that.”
Mitchell made eight changes from the World Cup final starting XV, which resulted in a lack of cohesion at times as his side attempted to play an open and expansive brand of rugby.
Scrum-half Lucy Packer, who played second fiddle to Hunt during the World Cup, looked lively throughout, while 22-year-old lock Lilli Ives Campion also stepped up in the line-out.
Fly-half Holly Aitchison was another player who struggled for starts at the World Cup but was handed the number 10 role from the outset.
“This is a new team, a fresh start and a learning process, and we have learned a lot today,” Mitchell told BBC Sport.
“Ireland were taken out of the match in the first half, but we let them back in, so we will learn from that.
“There is a huge amount of growth still to come – we are exposing youngsters and challenging the nine-ten axis.
“Players will be better for today’s performance.”
It will be interesting if Mitchell continues with his rotation policy or build cohesions, as England next face Scotland (13:30 BST) at Murrayfield next Saturday.
