|Full name||Marcos Javier Yáñez Fernández|
|Date of birth||10 April 1977|
|Place of birth||Boiro, Spain|
|Height||1.82 m (6 ft 0 in)|
|1998–1999||→ Pontevedra (loan)||28||(21)|
|2000–2006||Deportivo La Coruña||2||(0)|
|2000–2001||→ Elche (loan)||28||(6)|
|2001–2002||→ Poli Ejido (loan)||11||(1)|
|2003–2004||→ Las Palmas (loan)||34||(3)|
|2005||→ Pontevedra (loan)||15||(3)|
|2005–2006||→ Skoda Xanthi (loan)||1||(0)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 14 May 2017.
He played most of his career with Galician teams.
Having first played as a professional with SD Compostela, appearing in La Liga during the 1997–98 season by playing six matches and scoring one goal, against Racing de Santander in a 1–1 away draw, Changui went on to represent several second division teams before being purchased by Deportivo de La Coruña in 2002, although he would play almost no part during his tenure (two league appearances in the 2004–05 campaign, 13 minutes played), also serving a loan to UD Las Palmas.
In August 2005, Changui was again loaned, this time to Greek side Skoda Xanthi FC. Months later he came back to Spain without his parent club's permission, facing the subsequent and pertinent disciplinary proceedings; the player was summoned by Deportivo on 8 March 2006 but did not appear, sending instead his agent, who stated that he did not know about the player's departure from Xanthi until the Spaniards took action.
Finally, Deportivo cancelled Changui's contract on 9 June 2006. The latter reacted demanding the former for unpaid wages, having signed for Galician neighbours CF Extremadura in the previous year.
After being released by Extremadura, Changui joined SD Ciudad de Santiago in the fourth level. He helped it achieve promotion to division three in 2007–08 and, in 2009, resumed his career in the amateur leagues in his native region.
In October 2016, 39-year-old Changui was placed in an induced coma after being admitted to the Conxo Hospital in Santiago de Compostela with an extremely high temperature. He eventually recovered fully after being diagnosed with sepsis, and returned to playing football with his team Ribadumia CF.
- Racing y Compostela justifican su clasificación (Racing and Compostela account for their ranking); ABC, 9 March 1998 (in Spanish)
- Changui y el Deportivo acaban su vinculación en un juzgado social (Changui and Deportivo part ways in social court); El Correo Gallego, 9 June 2006 (in Spanish)
- Changui exige judicialmente 390.000 euros en concepto de salarios no abonados (Changui demands €390.000 in unpaid wages); La Voz de Galicia, 9 October 2007 (in Spanish)
- Changui y Maikel, una segunda juventud en el Ciudad de Santiago (Changui and Maikel, reborn in Ciudad de Santiago) Archived 26 March 2012 at the Wayback Machine.; Notas de Fútbol, 30 September 2008 (in Spanish)
- Changui: «Quiero volver a ser futbolista» (Changui: «I want to be a footballer again»); La Voz de Galicia, 29 November 2012 (in Spanish)
- Changui trae gol al Ribadumia (Changui brings goal to Ribadumia); Diario de Arousa, 26 January 2013 (in Spanish)
- Changui se recupera de un coma (Changui recovers from coma); La Voz de Galicia, 17 October 2016 (in Spanish)
- Changui recibe el alta y ya se recupera en casa (Changui is released and is already recovering at home); Diario de Pontevedra, 2 November 2016 (in Spanish)
- El Compos visita al Ribadumia en el regreso de Changui tras su grave enfermedad (Compos visit Ribadumia in return of Changui after his severe illness); Cadena SER, 14 January 2017 (in Spanish)