roundabout said:
Regarding Pereiro i don't think he spend as much time in Portugal as Mosquera. Also there was Milaneza-MSS who had invites to some big races (Paris-Nice, Romandie, Vuelta) so good riding on the domestic scene could be rewarded with a chance on the big stage.
Also, let us bear in mind that Mosquera is a Galician. Galicia is very close to Portugal, and until the creation of Karpin, it had no regional cycling team to speak of. Going to Portugal was more or less going to local teams for Mosquera, more so than going to one of the Spanish teams based in Navarre or Andalucía or Comunidad Valenciana. And if you dig back through his career, and where he's done well, there's not too much to say that it's a huge surprise:
2000 - 3rd, mountain stage of Volta a Portugal (to Gouveia).
2001 - 22nd, Volta a Portugal
2002 - 17th, Volta a Portugal
2003 - 6th, Trofeu Joaquim Agostinho (thanks to a mountain performance, behind Jeker, Valverde and Horrach), 3rd, mountain stage of Volta a Portugal
2004 - 7th, Volta a Portugal, with top 10s in all mountain stages
2005 - 8th Ruta del Sol, 5th Vuelta a Murcía, 15th, Vuelta a La Rioja (with a stage win and a 2nd in mountain stages), 10th, Volta a Catalunya (with 4th in the Arcalis ITT), 10th, Vuelta a Burgos (with a 4th to Lagunas de Neila).
2006 - 7th, Vuelta a Castilla y León stage to Navacerrada, 9th, Giro del Trentino, 8th, Clasico Alcobendas stage to Navacerrada, 9th, Vuelta a Burgos (with a 4th to Lagunas de Neila). Riding for Comunidad Valenciana impeded invites after Puerto, thus fewer race days than 2005 (with Kaiku) impedes development.
2007 - 11th, Vuelta a Comunidad Valenciana, 11th, Vuelta a Castilla y León, 5th, Vuelta a España (9th to Lagos de Covadonga, 9th to Arcalis, 3rd to Cerler, 9th to Abantos - so not mountain performances out of sync with his career to that point).
2008 - 10th, Vuelta a Murcía, 9th, Vuelta a Castilla y León, 9th, Vuelta al País Vasco (with a 2nd in one stage), 1st, Clasica Alcobendas (won stage to Navacerrada), 5th, Vuelta a Burgos, 4th Vuelta a España (2nd to La Rabassa, 11th to Pla de Beret, 7th to Angliru, 3rd to San Isidro, 6th to Navacerrada)
2009 - 6th Vuelta a Murcía, 8th Vuelta a Castilla y León, 4th Vuelta a Burgos (1st to Lagunas de Neila), 5th Vuelta a España (9th to Aitana, 13th to Xorret del Catí, 4th to Velefique, 2nd to Sierra Nevada, 4th to La Pandera, 6th to La Granja)
2010 - 3rd Vuelta a Castilla y León, 4th Vuelta a Asturias, 5th Vuelta a Madrid, 2nd Vuelta a Burgos (2nd to Lagunas de Neila), then this Vuelta.
If you look at it, he didn't really come from nowhere in 2007 - he had solid results in climbs in the major Spanish stage races before then, and had been pretty good in 2005 with Kaiku. He regressed a bit with Comunidad Valenciana in 2006 but they also had problems with invitations late in the season because of Puerto, which may have caused his previous good showings to fall from memory. And as he'd never done GTs before - but had placed well in the Volta a Portugal back when it was 14 stages - then if he had good recovery he was going to be well suited for them. If anything the 2009 calendar was his breakout year, with his placements in mountain stages being the best they'd ever been - but part of this was due to his strength and part of it due to other riders being less willing to attack. If you look at his results in 2010, they include races not previously mentioned or attempted seriously, so it could be that a change in his calendar has prepared him better for the Vuelta.