England fullback Mike Brown has admitted that his side's performance in the victory over France was far from the required level needed to defend their Six Nations crown.
The Red Rose began their title defence with a scrappy 19-16 triumph at Twickenham Stadium on Saturday to make it a national record 15-successive wins.
Boss Eddie Jones himself claimed after the match that England's performance was "disjointed", and Brown says a big improvement is required if the winning run is to continue when facing Wales in Cardiff next weekend.
"It's great to get the campaign off to a win but there's lots to work on and lots to improve," he told reporters. "It was a bit scrappy at times and we didn't do what we set out to do, but a win is a win. If we were looking for excuses we might say it was our first game, but we're not a team to do that.
"We didn't put out on the pitch what we wanted. We'd trained really well over the last two weeks, but just didn't do it. All credit to France because really disrupted our breakdown and then that has a knock on effect on everything else. We weren't physical enough. There's lots to work on.
"It's always a big game against Wales and it's an unbelievable atmosphere there. It will be a great game. It's a great stadium, it's one of my favourite stadiums to play at, but in the Six Nations every away game is special."
Scotland beat Ireland in their opening match of the 2017 campaign, while Wales take on Italy in Rome on Sunday afternoon.