Tristan's injury blow
Tristan picked up the problem while training for Spain's friendly clash with Northern Ireland on Wednesday and was immediately ruled out of the final World Cup warm-up.
The extent of the injury has yet to be determined but it is highly unlikely that the ace marksman will be fit for this weekend's summit meeting with Valencia.
Spanish doctor Genaro Borras said "He complained about pain in his left leg and it could possibly be a torn muscle."
If the problem is confirmed as a minor tear, rather than a strain, then Tristan's participation in Deportivo's title run-in is in jeopardy.
Following the battle with Valencia, Deportivo must face Malaga and Real Betis before a potentially decisive final day encounter with Real Madrid.
Tristan currently tops the scoring charts in Spain with 19 goals but his prospects of winning the 'pichichi' will also be in danger.
However, while Tristan's domestic campaign could be over, it is not thought likely that he will miss the World Cup finals.