Bryan Robson signed Keith O'Neill for his Premiership side Middlesboro on 16th March 1999 after months of speculation that linked Keith with Tottenham, Arsenal, Sunderland, Derby, Leeds, Leicester and Newcastle. Keith cost £700,000 which can be considered a bargain in that he was rated at £4million when Kenny Dalglish inquired after him for Newcastle two summers previously. The Evening Standard had reported in February 1999 that both Arsenal and Tottenham were keen on Norwich's want-away Irish star and planning £1.5million bids .Keith was slapped on the transfer list by manager Bruce Rioch after failing to agree a new Carrow Road contract in early October 1998. Following six weeks of fruitless negotiations the Canaries decided to cash in on O'Neill rather than risk seeing the 22-year-old Republic of Ireland striker walk out on a free transfer under the Bosman ruling next summer.

"Keith O'Neill is available for transfer as from now," confirmed Rioch on 7th October 1999. "We have made the decision reluctantly, but the club and the player have been unable to agree a new contract. Keith is out of contract at the end of this season and in a position to exercise his rights under Bosman without a fee being paid. You don't want to lose any good player, but these things do happen and the difference between the two parties is too great to bridge. Given the breakdown in negotiations this is the decision that has been made." Rioch declined to put a price on O'Neill's head, but it was clear City could not hope to rake in anywhere near the £4million they reportedly turned down from Newcastle. The young Dubliner's continuing ill-fortune with injury dramatically dented his market value, and with the clock ticking away towards the expiry of his contract on June 30 Rioch was keen to cut the club's losses on a depreciating asset. Rioch originally hoped for a fee of around £1.5million to £2million plus a potentially lucrative sell-on clause

Keith began his playing career with Dublin side Tolka Rovers at the age of 6 but transferred to Home Farm at the age of 13. He was spotted by Norwich at the age of 14 and invited over for trials with Mike Sutton's youngsters. Arsenal and Chelsea were also keen and he had visited the Gunners on several ocassions. However thy lost interest due to his injury niggles whilst Norwich showed faith and so he joined the Canaries. At the same time, he won his first international honours for the Republic's Under 18 side.

O'Neill made his first team debut under John Deehan in a 1-1 draw at Southampton in November 1994, but almost four years later it totaled just 55 first-team starts, 17 substitute appearances and eight goals. He was first spotted by the Canaries playing for the Home Farm in Dublin. At the end of the 1997/98 season, he had made 66 appearances for Norwich scoring a meagre 8 goals. His wish to escape Norwich for the bright lights of a big city and the Premiership did not endear him to Norwich fans. Especially as Norwich showed great loyalty to him when he was an injured youngster although this persuaded him to pledge his future to them "I agree that my service for the club hasn't been fantastic, but that's not through any fault of my own, and if I sign this contract and I'm flying and reach the heights I believe I'm capable of I'll still be stuck on that contract when I could have done better," pointed out O'Neill."I understand what people are saying. Some will say: 'He hasn't played, so good riddance'. Others will say it would have been nice to see me playing as they know I'm capable of playing. But there's two sides to every coin."It's just unfortunate that I haven't really reached the heights I think I'm capable of reaching, not through my fault or Norwich's fault, but through bad luck with injuries. Maybe if I do go somewhere else and make a fresh start I can start showing what I can do.I have got so much to look forward to in the future. I can't have bad luck all my career, and, when it stops the club I'm playing for will reap the benefits."

Keith was surprisingly transferred by new Boro boss Steve McLaren to Division One newcomers Coventry City on 8th August 2001 for a sum of £1million as Coventry hope to return to the Premiership. However injuries were again to prove his downfall and he was due to miss most of 2002 through injury. However he felt that he could still offer something to the game and in July 2002, non-leaguers Abingdon Town announced that Keith was to be their sponsor for the 2002/03 season with his name scrawled across their shirts. He would also provide the manager's player of the season award trophy. This bizarre sponsorship came via his cousin who lives in Abingdon.

On 25th April 2003, financially plagued Coventry, with debts of approximately £20million, announced that they were making available on free transfers, 9 first team players. O'Neill fell in this category along with Jay Boothroyd, Youssef Chippo, John Eustace, Lee Fowler, Morten Hyledaard, Julian Joachim, Gary McSheffrey and Barry Quinn. O'Neill stayed at Highfield Road due to contractual issues. During the close season of 2003, rumours started to circulate that O'Neill was close to fitness and manager Gary McAllister even publicly praised his attitude. O'Neill's remarkable comeback came on August 27 2003, 18 months after his last game, as a substitute in the game against Nottingham Forest. His comeback lasted just seven minutes before he was injured again, and substituted.

On 21st October 2003, Keith admitted defeat and announced his retirement through his back injury. "I talked to a couple of surgeons and, as much as I wanted to battle on, from medical advice, I had to call it a day. It's problems with my spine and back so it wasn't good and it's just unfortunate I've had to call it a day at such a young age. I doesn't stop me playing. I could quite easily play a game tomorrow, but not consistently week in, week out, so that wasn't good enough for Coventry City Football Club, so I understand their position. It's a sad day but I'm actually quite looking forward to it. I'm excited about the future, but it's just sinking in. I'm genuinely looking forward to it, even though I will miss it. It's the game I love but, obviously, my cards have been dealt now and I just have to get on with it.

Without a shadow of a doubt, the highlights have been playing for my country," he added. "I always dreamed of putting on the green shirt and playing for Ireland. I've met some great people. Bryan Robson was my hero since the age of four years of age, and he ended up buying me and is now a good friend of mine. Football's been good to me so no regrets, I've just got to get on with it. The world is my lobster! I'm a young lad!"

Keith was a regular on Sky Sports' Soccer Am until in mid-November 2004, Carlsberg South Western League club Newquay underlined their determination to join the elite of Cornish football by signing O'Neill. In an undoubted first for Duchy soccer, the 29-year-old forward joined former Republic of Ireland international team-mate Chris Morris at Newquay, and the one-time Middlesbrough and Coventry City player wowed the Mount Wise faithful with an impressive 60 minute display in the Peppermints' 7-0 humbling of Cornwall Cup holders Porthleven on his debut. Joint player-manager Dave Wilton said: "It's an exciting time for everyone involved with the club. From my point of view it's all about what he can offer in terms of training and guidance to our younger players, because he eventually wants to become an FA coach. What has been so nice is that Keith's such a laid back guy. He has settled in well and you wouldn't think he was such a big football name by the way he mixes with everyone in the dressing room. Just having two guys of the stature of Keith and Chris Morris is amazing - both on and off the field."