On 19 June 2013, Eraso was released by the Lions[3] and joined CD Leganés also of the third division the following month.[4] He appeared in 42 games during the campaign, as the Madrid club was promoted to Segunda División after a ten-year absence.[5]
Eraso played his first match as a professional on 7 September 2014, starting in a 3–1 home win against RCD Mallorca.[6] He scored his first goal in the second tier on 21 December, the last in 2–0 home victory over Recreativo de Huelva.[7][5]
On 31 May 2015, Eraso scored a hat-trick in a 5–2 away rout of FC Barcelona B.[8] On 1 July he returned to Athletic, now being assigned to the first team in La Liga.[9]
Eraso returned to Leganés on 24 July 2017, with the side now competing in the top division.[12] He went on to make 215 competitive appearances over two spells at the Estadio Municipal de Butarque,[13] being relegated in 2019–20.[14]
On 4 July 2022, Eraso moved abroad for the first time in his career, with the 32-year-old signing a two-year contract with Cypriot First Division newcomers Akritas Chlorakas.[15] On 12 July of the following year, he returned to Spain and its second division after agreeing to a deal with SD Amorebieta.[16]
^Martínez de Zúñiga, Uxue (12 May 2020). "Tajonar, la cantera de España" [Tajonar, Spain's youth system]. Diario AS (in Spanish). Retrieved 27 April 2022.
^"Contrato de Javier Eraso" [Javier Eraso's contract] (in Spanish). Athletic Bilbao. 1 July 2015. Archived from the original on 28 August 2017. Retrieved 1 July 2015.