Sir Clive Woodward believed England would annihilate Wales by more than 30 points until Manu Tuilagi's withdrawal on Thursday night.
Woodward still thinks England will win at Twickenham today, but by a reduced margin.
Writing in his MailOnline column, he says a big England performance is coming, with Eddie Jones' mobile team selection meaning they can counter Wales' kicking game to devastating effect.
Read next: The latest England v Wales headlines
Woodward wrote: "What a difference a day makes. Or indeed half a day. On Thursday morning England had picked a great team and I was full of optimism for the first Six Nations game in front of a full house at Twickenham since hosting Wales in 2020.
"However, by Thursday night the news of Manu Tuilagi’s latest injury broke and at a stroke the team immediately lost its X-factor. You could almost hear the sighs of relief down in Wales.
"Many were predicting a close game but I was expecting England to win by 30 points or more.
"Manu was going to light the touchpaper, but now I am back among those expecting a much closer game — although I am still going with an England win.
"Wales have won two of the last three Championship encounters with England and scored 91 points in the process, so they won’t go easily but my gut instinct tells me England have a big performance brewing.
"Why am I so confident? Because England have finally selected a team capable of playing rugby in the fast lane and scoring tries quickly. If they can gain ascendancy they can build a score quickly."
Woodward is one of many pundits predicting an England victory, with the likes of Will Greenwood, Matt Dawson and Andy Goode all confident the home team will ease past Wales.
Many Welsh pundits are also predicting an England win, albeit by a much smaller margin.
Former Wales captain Sam Warburton doesn't think a Welsh shock is impossible though.
He wrote in the Times: "If you had asked me after the defeat in Ireland I would have said that Wales have not got a chance, but I just loved how they went back to type against Scotland.
"They can do the same again here. England are clearly favourites, and call me mad if you will, but it wouldn’t surprise me if Wales do really well."
To get the latest rugby news sent straight to you, sign up for our Welsh rugby newsletter.
