Welsh 400m runner Tim Benjamin is confident he will return to his best form after his first winter training with new coach Colin Jackson.
Benjamin is targeting his personal best of 44.56 seconds
Benjamin, 25, was ranked fourth in the world in 2005 but saw his progress stall last season because of injury.
Benjamin races in Belgrade and Glasgow next week and told BBC Sport: "I want to get to where I left off in 2005 and run under 45 seconds again."
Jackson said: "It'd be great for Tim to come back after a fallow season."
The former 110m hurdle world-record holder and two-time world champion started working with Benjamin last September.
He persuaded the 25-year-old to move back to his hometown of Cardiff after the 400m runner decided to leave his coach Tony Lester.
Jackson began by altering Benjamin's training schedule to include greater emphasis on building up his core strength and muscles, but is cautious about predicting when those changes will reap rewards.
People's expectations on Tim are huge but I don't expect him to go backwards in any way
"There is no short or long-term objective," insisted Jackson. "Every year we just want to improve.
"The biggest difference you will see in Tim this year is his physical stature, he is a lot stronger now and is comfortable with that.
"People's expectations on Tim are huge but I don't expect him to go backwards in any way."
Benjamin will get his first runout of the season in Belgrade on Tuesday before racing on British soil for the first time this summer at next Sunday's Glasgow Grand Prix.
A groin injury forced him to miss the 2006 Commonwealth Games and then saw him finish sixth at the European Championships - a result he describes as the worst performance of his career.
But after a largely injury-free winter, Benjamin is ready to test himself against the world's best at this summer's World Championships in Osaka, Japan.
"It's always a tough year and it will be again this time," said Benjamin, who has a personal best of 44.56 seconds.
"Last season the 400m went to another level with Jeremy Wariner (the Olympic and world champion) at the top running 43.6 seconds.
"The depth of the 400m is as good as it's ever been but I'm aiming to get a place in the final of the Worlds. I've just got to roll with the punches and get in there."
New British javelin world-record holder Goldie Sayers will join Benjamin in Glasgow, where she hopes to improve on her mark of 65.05 metres.
Sayers, however, faces a tough field that includes all three medallists from the European Championships; Steffi Nerius, Barbora Spotakova and Mercedes Chilla.
Portugal's European 100 and 200m champion Francis Obikwelu has been added to the line-up as he goes against Britons Christian Malcolm, Marlon Devonish and Tim Abeyie over 200m.
Watch the Norwich Union Grand Prix live on BBC TWO on Sunday 3 June between 1500-1700 (BST).