ReutersEspanyol and Getafe, along with two Premier League clubs, were rumoured to be keen on landing the 27-year-old striker, but Rubin have won the race for his signature.
Valdez, who joined Hercules in 2010 and scored eight goals in 25 appearances, is believed to have cost Rubin €5million (£4.3m) and has signed a four-year contract with the Russian outfit.
The Alicante-based side, Hercules, were relegated to the Segunda division at the end of the 2010-11 season and their poor financial state meant they had to cash in on the star striker.
