Mann has encouraging personal memories of Twickenham, having scored 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.
“It is big game for the country so we’re going to do everything in all powers to get our win on Saturday,” said Mann.
“It’s a big occasion, it means a lot to the Welsh people and the Welsh fans.
“So we know that it’s our job to go and put a performance in for Wales.”
England have won their past 11 internationals, including four victories in the autumn campaign, which has lifted them to third in the world.
In contrast, Wales have lost 21 out of 23 internationals with the only victories against Japan in Kobe and Cardiff in 2025.
The run of defeats included an unprecedented 18-match successive Test losing sequence and record home losses 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 the record of 11 successive defeats resulting in two winless tournaments.
But Mann says he is not concerned with Wales being written off.
“We have that inner belief as a group so it doesn’t matter what other people say outside because that’s irrelevant,” he added.
“We know what we can do and the calibre of players we have got, so we have that self-confidence that we can go and put a performance in and turn teams over.
“That’s the exciting bit for us.”