Lara, 37, told reporters after West Indies defeated Pakistan by seven wicket in the fourth one-day international that it was important for him to get runs in the World Cup.
"As it is I don't think I will be playing one-day internationals after the tournament," he said.
Lara said West Indies' victory, which cut Pakistan's lead in the five-match series to 2-1 after the first match was abandoned, had been exceptional.
"The boys showed a lot of character today. They bowled well today," he said.
"We just need to go in with a positive frame of mind for the last game in Karachi. It is important we win that because it would be a big psychological boost for us before the World Cup to square the series in Pakistan.
"At the age of 37 I know what is expected of me. The form has been sketchy but I want to fire in the World Cup which is such an important tournament for us as the hosts."
