Andy Farrell says he is in his best shape for years as he tries to clinch a place in England's World Cup squad.
Farrell has won three England caps since switching codes
England boss Brian Ashton said he is looking for a "big performance" from the former Great Britain rugby league captain against Wales on Saturday.
"I would think it was 2004 when I was last fully fit," said Farrell.
"I have had six weeks of really intense training, three or four sessions a day. Six months ago, I wouldn't have been able to have done that."
Competition for the centre spots in Ashton's 30-man squad is intense.
Mike Catt and Mathew Tait are tipped to be on the plane, while Dan Hipkiss, Jamie Noon, Toby Flood, Mike Tindall and Olly Barkley are all in contention along with Farrell for the probable two remaining slots.
Since his move to the union code Farrell has struggled to make a big impact, with injury frequently halting his progress, and he has won only three caps.
The Saracens centre's cause was not helped when illness ruled him out of England's two Tests against South Africa in May and June, but Ashton believes luck is turning his way.
Some people might see it as a trial game but I suppose every time you play for your country it is a type of trial game
England centre Andy Farrell
"For the first time since Andy switched codes, he is training injury-free," said Ashton.
"He looks a lot fitter than he was when he played for England in the Six Nations last season and, consequently, he looks more the player that he was when he switched codes than he did when he started playing for Saracens last season."
Farrell admits he is under pressure to prove he is worth a place in France.
"Some people might see it as a trial game, but I suppose every time you play for your country it is a type of trial game anyway because you always want to play in the next game," he said.
"The main thing for everyone in the team is to try and put together what we have been doing for the last five or six weeks and get this team moving forward towards the World Cup."
Against Wales he will play alongside 25-year-old Leicester centre Hipkiss, who was unavailable for the summer tour and will be making his debut in an untried partnership.
"Dan Hipkiss deserves his chance," said Ashton.
"He played really well in the second half of the Premiership this season and in the Heineken Cup as well and certainly would have gone to South Africa had he not been involved in the later stages of the play-offs and the Heineken final."
Hipkiss was part of the Leicester team which won the EDF Energy Cup and Guinness Premiership title and lost the Heineken Cup final and he thinks that big-match experience will help him keep his nerves under control on Saturday.
"I've played in three finals this year at Twickenham," he said.
"I've got a lot of homework to do on the Welsh before leading up to Saturday, so I don't want to play the game too soon in the week."