Borussia Dortmund are reported to have contacted the Greek Football Federation ahead of Monday's meeting with Germany, asking for Karetsas to be protected after the teenager started Greece's previous three matches.
The 18-year-old midfielder has become an important player for his country despite his age, but Jovanovic has made clear that clubs will not receive preferential treatment when he selects his team.
“Since I have been the national coach, there has not been a club in Europe that has asked us for special treatment. As long as I am coach, there will be no exception,” Jovanovic said during a media conference.
Sky reported that Dortmund made contact with the Greek federation because Karetsas had started each of Greece's previous three matches.
The request comes as clubs increasingly seek to manage the workload of young players who are playing regularly for both their national teams and their clubs.
Jovanovic nevertheless stressed that Greece maintains regular communication with clubs and will generally try to be accommodating where possible.
That does not mean, however, that Dortmund can dictate whether Karetsas plays against Germany.
The midfielder is expected to remain available for the match, with Jovanovic insisting that his selection decisions will continue to be based on the needs of the national team.
Karetsas' involvement has become particularly notable because of his age and the demands already being placed on him at club and international level.
Dortmund's reported intervention highlights the importance they attach to managing his workload, but Jovanovic's response shows that the final decision remains with Greece.
The coach has drawn a clear line over requests from European clubs, making it clear that there will be no special arrangement for Dortmund.