The 35-year-old linked up with his former club late last month following his release by Mexican side Pachuca.
Tamudo said: "I am here with all the desire in the world.
"Now I hope to be another player who can help, like I always want to do. The team has been doing well and now I hope that I can help them go on to celebrate something.
"This is a moment to enjoy now the team are doing well and pushing for the positions at the top end of the table.
"When [sporting director] Felipe Minambres called me I was pleased because it was unexpected and I had thought that there wouldn't be any more chances for me to play in Spanish football."