Born in Corcubión, Province of A Coruña, Polo played his entire professional career with CeltadeVigo also in his native Galicia, after Real Fortuna Football Club merged with Real Vigo Sporting Club in 1923.
He made over 125 appearances in England's Premier League with Liverpool, Sunderland and Newcastle United, and reached the Coupe de France final with Marseille in 2016.