Mann has inspiring personal memories at Twickenham, scoring a try in the 16-14 defeat against England in 2024 in what was only his second international.
Despite the loss, the occasion gave him a glimpse of the importance of the fixture.
“This is a big game for the country so we will do everything in our power to get our victory on Saturday,” Mann said.
“It’s a big occasion, it means a lot to Welsh people and Welsh fans.
“So we knew it was our job to go and put on a show for Wales.”
England have won their last 11 internationals, including four wins in the autumn campaign, which lifted them to third in the world.
In contrast, Wales have lost 21 of 23 internationals with the only wins coming against Japan in Kobe and Cardiff in 2025.
The losing streak included an unprecedented 18-match Test losing streak and record home defeats against England (68-14), Argentina (52-26) and South Africa (73-0).
Wales have not won a Six Nations match since March 2023 against Italy in Rome, with a record 11-game losing streak resulting in two winless tournaments.
But Mann said he was not worried about Wales’ dismissal.
“We have that inner faith as a group so it doesn’t matter what other people say outside because that’s irrelevant,” he added.
“We know what we’re capable of and the caliber of players we’ve got, so we’ve got the self-belief that we can go and put on a show and bring those teams back.
“That’s the exciting bit for us.”