Viana playing for Litex Lovech in 2015
|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)|
|2016||Litex Lovech II||8||(0)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 16 May 2019|
Born in Lagos, Algarve, Viana spent six years as a youth at Sporting CP. In June 2008 the 18-year-old was transferred to FC 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 debut with the first team, playing four Portuguese League Cup matches and totalling 55 minutes in two wins and two losses; his first appearance was against Vitória de Setúbal (2–1 home win), on 8 January 2009.
On 17 June 2009, Viana moved on loan to VVV-Venlo in the Netherlands. He appeared in 23 Eredivisie games in his first year, helping the Limburg side finish in 12th position. In January 2011 he returned to Portugal and joined C.D. Aves of the second division, in the same situation.
Viana signed with First Professional Football League (Bulgaria) club PFC Litex Lovech in June 2015, after two years in the Primeira Liga with Gil Vicente FC. In the summer of 2016 he joined PFC CSKA Sofia on a free transfer, after the former merged with the latter.
- "Postiga leaves Porto for Sporting". UEFA. 1 June 2008. Retrieved 15 April 2011.
- "Comunicado" [Announcement] (PDF) (in Portuguese). Portuguese Securities Market Commission. 1 June 2008. Retrieved 4 October 2010.
- "FC Porto bate Vitória de Setúbal com tento de Rabiola" [FC Porto beat Vitória de Setúbal with Rabiola goal] (in Portuguese). Rádio e Televisão de Portugal. 8 January 2009. Retrieved 30 October 2017.
- "Diogo Viana chega por empréstimo" [Diogo Viana arrives on loan]. Record (in Portuguese). 10 January 2011. Retrieved 30 October 2017.
- "Литекс представи Диого Виана (СНИМКИ). 25-годишният португалец взе номер 7 при "оранжевите"" [Litex present Diogo Viana (PHOTOS). 25-year-old Portuguese took the number 7 at the Orange] (in Bulgarian). Blitz. 24 June 2015. Retrieved 15 August 2016.
- "Diogo Viana assina por dois anos" [Diogo Viana signs for two years] (in Portuguese). SAPO. 13 June 2013. Retrieved 30 October 2017.
- "ЦСКА продаде Диого Виана на Белененсеш" [CSKA sell Diogo Viana to Belenenses] (in Bulgarian). CSKA Sofia. 31 January 2017. Retrieved 1 February 2017.