Former Ireland and Munster centre James Downey believes the back row battle will be crucial when Andy Farrell's side take on England in Sunday's Guinness Six Nations clash at Twickenham.

It is the first time Ireland will face Eddie Jones' side since two chastening defeats in 2019, including in last year's Six Nations opener in Dublin.

The 2020 campaign has been more positive from an Irish perspective, with home wins over Scotland and Wales, while England slipped up in France before edging Scotland in difficult conditions at Murrayfield.

Despite England's less impressive 2020 so far, Downey told RTÉ Sport that the physicality of Jones' team will be something Ireland will need to be wary of after last year's experience.

"England's a different story altogether," he said.

"The physicality they brought in the second half especially against the French is one we have to watch out for.

"Also I think if Ireland play the way they want to play, get it to space if they can and bring that new way of playing and new confidence, it will be an interesting test between the two teams.

"I don't know if Ireland will have had enough time to change a few things but ultimately it's going to come down to being a tight game and if we can get that momentum up, it will bode well."

But it is the back row where Ireland could thrive given the form of CJ Stander and Josh van der Flier in particular, coupled with England struggling to fill the number eight position adequately during this championship.

"It's certainly going to be a massive area. I think up front is going to be a whole huge area but I think you look at missing Billy Vunipola, that is huge for England," said Downey.

"But I have been extremely impressed with how CJ Stander has played and the whole back row really, Josh van der Flier's been around doing exactly what he does, making hundreds of tackles and Peter O'Mahony has been a nuisance.

"But CJ has been the standout back-rower at the moment. He hadn't had the best of times but he has answered all his critics and performed extremely well.

"It could be an area where we can get a one-up on the English."

Tune into Against The Head at 8pm on RTÉ2 featuring James Downey, Bernard Jackman and Eddie O'Sullivan.

Tonight's show will also feature a tribute to former Munster CEO Garrett Fitzgerald, an interview with Ireland's Linda Djougang and a preview of Ireland's Twickenham trip as well as AIL action and discussion on the changing global rugby landscape.