The 23-year-old has proved his goalscoring skills in Dutch Eredivisie over the last couple of years and has in turn seen his name linked with a number of high-profile clubs.
Il Corriere dello Sport reports that Arsenal, Borussia Dortmund and Newcastle are all keeping close tabs on the Icelandic forward, but the problem is Ajax are not yet prepared to sell.
Sigthorsson has two years left on his deal at Amsterdam ArenA, with the Amsterdammers hoping they can persuade the player to extend his contract.
Legendary coach Louis van Gaal was the first one to spot the player’s potential and eventually lured him to AZ Alkmaar in January 2008.
After spending two and a half years playing for club’s youth sides, Sigthorsson went on to score 15 goals in 31 Eredivisie matches for AZ Alkmaar during the 2010/2011 season, before signing for Ajax.
Sigthorsson has bagged a total of 16 goals in 32 Eredivisie matches for the Dutch giants, winning two league titles in the process.