The Argentina captain has been in discussions over a new deal for three months and it was anticipated an agreement would be reached by the end of the season.
Now that has not happened it leaves open the prospect that a good tournament for the 25-year-old will lead to more speculation over his future.
A seventh-place finish in the Premier League means the club will begin their Europa League campaign in the third qualifying round , which starts on July 29.
Boss Rafa Benitez is obviously not happy about the scenario but begrudgingly accepts it is something which is happening more regularly.
"We have to prepare. We have pre-season more or less organised and we now have to analyse carefully the schedule and see if we can organise the fixtures properly," said the Spaniard.
"Last year we had too many players away with the Confederations Cup (also in South Africa) so the teams are suffering with these tournaments and every year it is more and more so it is not easy."