|Full name||Diogo Filipe Guerreiro Viana|
|Date of birth||22 February 1990|
|Place of birth||Lagos, Portugal|
|Height||1.73 m (5 ft 8 in)|
|2009–2010||→ VVV (loan)||33||(1)|
|2011||→ Aves (loan)||9||(0)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 6 July 2014.
† Appearances (Goals).
Born in Lagos, Algarve, Viana spent six years as a youth at Sporting Clube de Portugal. In June 2008 the 18-year-old was transferred to F.C. Porto as part of a deal involving Hélder Postiga, with the northerners receiving €2.5 million whereas the Lisbon club retained 50% of his rights. In the 2008–09 season, whilst still a junior, he made his debuts with the first team, appearing in four Portuguese League Cup games and totalling 55 minutes in two wins and two losses; his first match was against Vitória de Setúbal (2–1 home win).
On 17 June 2009, Viana moved on loan to VVV-Venlo in the Netherlands. He appeared in 23 Eredivisie contests in his first year, helping the Limburg side finish in 12th position. In January 2011 he returned to Portugal and joined C.D. Aves in the second division, in the same predicament.