The 33-year-old was signed by former Cardiff manager Ole Gunnar Solskjaer in May 2014 with a big goal-scoring reputation – having scored 72 times in 149 games for Real Valladolid – but he has had a nightmare time in South Wales.
Solskjaer left Cardiff within four months of his arrival and Guerra made only two League Cup starts and three substitute appearances in the league for the Bluebirds, failing to find the net once.
Guerra was sent out on loan to Primera Division club Malaga for the second half of the 2014-15 campaign and current Cardiff boss Russell Slade said the striker could return to Spain after that spell.
“The situation in sporting terms is not good and I imagine we need to try to reach an agreement and terminate the contract,” Guerra told BBC Radio Wales.
“It’s not that it’s difficult, it’s just the mentality or the way you see football is different in Spain.
“At the beginning the adaptation wasn’t easy… with people saying this player isn’t worth the money or we don’t like this player.
“I blame both myself and the club to have not succeeded.
“The club didn’t have confidence in me and I found it hard to adapt to English football.
“Any player wants to feel valued in his team or at least have the chance to play and I haven’t had it here since I signed for this team.”
Guerra scored five goals in 13 league appearances for Malaga and admits returning to play in Spain is his preference.
“For me, Spain, as it is my country – and I know the league – it would be much better and I wouldn’t need to adapt,” Guerra said.
“There are clubs that are watching, that are aware of the situation.
“I would like to reach an agreement with them, I cannot say who they are.”