Speaking to the media, Maresca said: "I spoke with Mischa in Poland when we played the Conference League final. I haven’t spoke with him since then.
"I didn’t see the news but they communicated it to me but there is nothing more I can add because I don’t have more information.
"Last time I spoke to him he was quite good, I didn't see him worried, I didn't speak to him since then so I don't know but for sure we will have contact with him."