Barcelona boss Pep Guardiola has alerted Chelsea after he hinted he may delay a year-long sabbatical if a club "seduces" him.
Guardiola was speaking ahead of the Catalans' Copa del Rey final with Athletic Club Bilbao this evening when he gave the first signal he may renege on his initial pledge.
"I will receive all calls with pleasure, but for the next month I have to recharge my batteries and my mind.
"I will be ready [to return] if one club wants me and seduces me."
Champions League winners Chelsea are keeping their options open despite Roberto di Matteo's extraordinary success as interim coach in under three months.
The Italian had already guided the club to an FA Cup win before last week's success against Bayern Munich, but owner Roman Abramovich is believed to be reluctant to offer him a lengthy deal.
He is also a known admirer of 41-year-old Guardiola, and his desire for Chelsea to play positive attacking football has led to previous managerial departures.
The pragmatic Jose Mourinho's downfall was ostensibly partly due to his Blues' approach, while Di Matteo's tactics since his promotion from assistant in March have been resoundingly negative.