After starting his professional career at local Celta, he played in England with Birmingham City in 2007, but his spell was immediately cut short with a severe knee injury, which would relapse in the following years.[2] He appeared in 236 competitive matches for his main club, with whom he spent five La Liga seasons.[3]
After Celta's top-flight relegation in the 2006–07 campaign, Oubiña stated his desire to leave although still under contract. As of August, it seemed that countryman José Antonio Camacho's S.L. Benfica were in the pole to acquire his services, but an agreement could not be reached on a fee – rumoured to be €10 million.[5]
On 9 February 2008, Oubiña's loan spell at Birmingham was cancelled by mutual consent,[8] and he returned to Vigo to start his recovery. On 6 December, more than a year after his last appearance, he played four minutes in a 2–0 loss at UD Las Palmas, and made a further 14 appearances in the season; he relapsed in mid-September 2009, and underwent surgery in October preparatory to the planned reconstruction of his cruciate ligament in early 2010, after which he would miss the remainder of 2009–10.[9]
Oubiña returned to full fitness in the 2011–12 campaign,[10] playing 28 matches (24 starts, 2,120 minutes of action) as Celta returned to the top tier after a five-year absence.[11] In 2014–15, however, he again failed to appear in any games due to injury.[12]
On 22 May 2015, five days after his 33rd birthday, Oubiña announced his retirement.[13]