Say Villarreal is in 1st and Madrid is playing 2nd place Valencia. Could Villarreal loan one of their best players to Madrid in an attempt to knock off Valencia?
yes they can but it is dificult to imagine for some very big reasons:
-Many countries, including all UEFA members, do not permit loans to commence beyond a transfer deadline for each season. (only two transfer windows in Liga, summer-before start of liga, winter-january, Clubs can not change the players after the 2nd transfer window in winter). Then sometimes a loan may be made to circumvent a transfer window. Such a loan might include an agreed fee for a permanent transfer when the next transfer window opens.
Villareall will probalby need all their best players during Liga, CL and Copa, no time to think about other clubs.
The big clubs including Villarreal send players on loan to smaller clubs but no rival teams like Real or Valencia.
Just one more thing: Cazorla, euro 08 winner, start in Villarreal was near to sign for Real this summer but he preferred to stay in Villarreal.
The face of Cazorla in his penalty against Buffon this summer in Vienna was unforgettable, all the struggles of past penalties tragedies in a player. he celebrated in fashion. Senna is awesome!