Sparta Prague coach Jozef Chovanec says no offers have come in for midfielder Juraj Kucka.
Sunderland and Blackburn Rovers are keen on Kucka.
"We don't hide the fact that we expect suitors to be interested in our players after progressing in the Europa League but so far no specific offers have appeared on the table," he told Idnes.
"As soon as someone comes in with a specific offer, we will discuss it. But not with some agent, it must be a person from the respective interested club."
Sunderland were understood to have sent a scout to check on Kucka in their 1-1 draw with CSKA Moscow on Wednesday.
Chovanec refused to confirm Sunderland's presence at the match.
"Were Sunderland present here at the CSKA game to watch Kucka? 23 international scouts were present."
