The winger, who turns 30 next week, said that, after a decade in total in the Celtic League, he was looking forward to new surroundings.
“My six years at the Ospreys have been the best of my career and I’m sad to be moving on,” Walker said. “I’ll leave the Ospreys with so many happy memories, and I’d like to thank everybody for making me feel at home.
“But, after ten years playing in the Celtic League, I feel that the time is right for me to try a fresh challenge in England.”
A powerful winger, Walker made his name in club rugby with Hawick before turning professional with the Border Reivers. He made his international debut in 2002 against Romania, was a squad member in the 2007 Rugby World Cup and has won 24 caps. He played in four of Scotland’s matches in last year’s RBS Six Nations Championship, but missed out on last year’s Rugby World Cup after sustaining a cruciate ligament injury in the warm-up game against Italy.
Since moving to the Ospreys in 2006 he has played over 100 games for the Welsh region, scoring 37 tries.
In that time Walker has won two Celtic League titles, played in the EDF Energy Cup final against Leicester Tigers two years running and also played in the club’s victory over the Australian tourists.
“Everybody at the Ospreys have always been fantastic to me, particularly over the last year while I’ve been injured,” Walker continued. “The medical team, coaches and management have been great, while the fans have always given me their full support.
“I’ll leave the Ospreys with so many happy memories, and I’d like to thank everybody for always making me feel at home during my time with the region.”
Walker has not played for his club this season because of his knee injury, but is now close to full fitness and has every chance of playing a prominent role in Worcester’s campaign next season.
“We have signed a physical and explosive player with real experience who will add a huge amount to the club,” Worcester head coach Richard Hill said yesterday. “We are striving to improve our squad and so we’re delighted to have an international player of Nikki’s pedigree coming in. Nikki has played Heineken Cup and international rugby, including at a Rugby World Cup. He will bring that experience to Sixways and, if we are going to move upwards, we have to bring in people who have played at the very highest level.
“He will also bring a different style. At Ospreys he was used in conjunction with Shane Williams and added a real threat around the 10 channel. It opened up space out wide and, if he can do that at Warriors, it will allow our other wingers to exploit that room. Nikki also has a fantastic attitude and is a real club man who will embrace the culture and environment we have here at Sixways.”
Walker’s impending departure from the Liberty Stadium adds to a growing list of big names who have opted to leave the Ospreys. Former Wales winger Williams is to retire at the end of the season, and Irish international Tommy Bowe has been linked with a return to Ulster, in which case the Welsh region will have lost three international wings.
Hooker Huw Bennett is moving to Lyon in the summer, and back-row forward Tom Smith will join London Irish. Last season scrum-half Mike Phillips, stand-off James Hook and utility back Lee Byrne all left for French clubs, Gavin Henson moved to England, and forwards Jerry Collins, Marty Holah, Filo Tiatia and Craig Mitchell all also left.
Wales prop Adam Jones has agreed a new two-year contract with the team but there is no doubt that the Ospreys squad is still in considerable need of strengthening if the team are to contend towards the upper half of the RaboDirect Pro12 league table next season.
Worcester, by contrast, look like a club who are steadily making pogress. Lying tenth in their first season back in the Aviva Premiership and with a 14-point lead over bottom club Newcastle Falcons, they are all but certain of holding on to their place in the top flight of English rugby.