The Czech Republic man was a key performer at Euro 2012, and his fine form has prompted interest from several clubs as his contract comes to an end in Turkey
The centre-back caught the eye during Czech Republic's Euro 2012 campaign, where he helped his side to reach the quarter-finals with a string of solid performances.
Sevilla had looked likely to sign the 28-year-old, but his agent Jiri Mueller now claims that the Spanish club must see off interest from England in order to complete the deal.
"We have opened official talks with Sevilla and would like to have things sorted out as soon as possible," Mueller told CTK.
"We also have registered interest from a club in the Premier League and Besiktas have come back into the race as they want to keep Tomas."
Sivok has made 30 international appearances for the Czech national team, scoring three times.