"But I am so fortunate to have such a great support base. I would like to say a very special thank you to my family, girlfriend, friends and Leinster team-mates who have been so supportive - especially over the last few months.
"I owe an awful lot to my team-mates and all of the staff at Leinster. Naturally, as with any long term injury, you inevitably end up spending a lot of time with the physiotherapists, the strength & conditioning coaches and the doctors, so I would like to say a particular thank you to them.
"People often refer to modern day sport as a ruthless and cut-throat environment but Leinster have without a doubt gone above and beyond in all aspects, doing everything they could in attempting to help me with my recovery.
"I would also like to strongly thank Michael Cheika, Joe Schmidt and all of the great coaches I've played under for their support since my schooldays.
"At the age of 25, it is surreal to be reflecting on your career, especially when I hoped there were many more years ahead for me.
"Having had a bit of time to reflect on this day coming I look back with real pride, firstly by getting into the Leinster Academy and then progressing up the ranks to a Leinster squad who would go on to have such a successful number of years.
"To have played a small part in my home province's success is something I dreamt about since I was a child and it will always mean an enormous amount to me. It was always a great honour to pull on the Leinster jersey and they are memories I will never forget."
Paying tribute to O'Malley, Leinster team manager Guy Easterby said: "First and foremost, Eoin's retirement is a significant loss to the squad because not only is he a superb player with a huge amount of talent, he is also a great bloke who is well respected by both his fellow players and all the staff here at Leinster Rugby.
"He has been unfortunate in having a couple of serious injuries during his career but he has always shown the utmost professionalism and he has been a real example to all of the players.
"It is sad that a player with so much potential has to end his career at this point, but he does so with our sincere thanks for his contribution to Leinster's success.
"A hugely popular man, he can look back on his career with great pride and we wish him well with the next chapter in his life."
Dubliner O'Malley played a key role in the province's recent successes in both the domestic competitions and in Europe, where he was a regular in the Leinster midfield, featuring a total of 54 times in the end.
The centre excelled at an early age when studying with Belvedere College, whom he helped lift the Schools Senior Cup in 2005 alongside then team-mates and great friends Cian Healy, Ian Keatley and Paul O'Donohoe who all went on to enjoy professional careers following starts with their home province.
Eoin earned a number of caps for both the Leinster and Ireland Schools selections and went on to play with Old Belvedere in the Ulster Bank League and graduated from the Leinster Academy.
In December 2009, O'Malley made his senior competitive debut for the province in an away loss to the Newport Gwent Dragons.
Wins followed in his next four Leinster appearances and he finished the season with seven caps in total. He also lined out for the British & Irish Cup side on a number of occasions.
The transition from promising squad member to regular starter was a rapid one as he featured in 18 Magners League games over the course of a season that saw Leinster lose out to Munster in the league's grand final.
O'Malley registered his first Leinster try with the opening salvo in a 17-17 draw with the Scarlets and made two appearances in Europe during a Heineken Cup-winning season.
He ran in the sixth try in a pool win over Saracens on the province's march to success at the Millennium Stadium.
Greater responsibility was thrust upon O'Malley in the Leinster back-line at the beginning of 2011/12 as several team-mates were on World Cup duty with Ireland. He did not disappoint and caught the eye in PRO12 victories over the Scarlets, Connacht and Edinburgh.
The centre scored two fantastic tries to secure Leinster a bonus point victory over Glasgow in the pool stages of the Heineken Cup. He kept up the scoring habit with a try against Benetton Treviso some six days later.
He appeared in home and away Heineken Cup clashes with Bath and started a comfortable home triumph over Montpellier that ensured the Blues would top their pool.
In total, O'Malley played 22 times for the province in a season that would deliver a second successive Heineken Cup.
Capped 10 times with Ireland Under-20s, the Dubliner featured three times for the O2 Ireland Wolfhounds team and was called into the extended training squad for Ireland's 2012 Six Nations campaign.
However, his 2012/13 season was dogged by injuries. Although he recovered sufficiently to play five more times for the province, the knee injury never fully recovered and he was left with no choice but to hang up his boots following consultations with a number of medical teams in Ireland, Europe and America.
Paying tribute to his retiring Leinster team-mate, Brian O'Driscoll tweeted today: "Absolutely brutal to see Eoin O'Malley having to retire. Very clever player and a great man to have in your dressing room. #Massiveloss"
EOIN O'MALLEY -
Date of Birth: July 6, 1988
Height: 1.78m (5ft 10in)
Weight: 90kg (14st 2lb)
Club: Old Belvedere RFC
School: Belvedere College SJ
Leinster Caps: 54 (7 in Heineken Cup)
Leinster Tries: 5 (3 in Heineken Cup)
Leinster 'A' Caps: 8 (v Ulster x5, Edinburgh, Munster x2)
British & Irish Cup Caps: 5 (v Plymouth Albion, Cornish Pirates, Exeter Chiefs, Newport, Jersey)
Ireland 'A' (Wolfhounds) Caps: 3 (v Scotland, England x2)
Ireland Under-20 Caps: 10 (v Italy x2, France, Scotland, Wales, England, Argentina x2, New Zealand, Tonga)
Leinster Under-20 Caps: 3 (v England Midlands, Ulster, Connacht)
Ireland Under-19 Caps: 7 (v Wales, Italy, Australia, Scotland x2, South Africa, Japan)
Ireland Schools Caps: 4
Leinster Schools Caps: 4