It has been reported that West Ham are ready to pay €20 million (£16.77m) in order to secure the services of the 22-year-old striker this summer.
This is an interesting twist in the transfer saga, as the youngster himself has made it clear that he wants to join Tottenham Hotspur in the summer transfer window.
Interestingly, ESPN reported earlier today that the North London outfit should compete the deal to sign Janssen this week.
Janssen is a talented young striker, and it is almost inevitable that he will leave AZ.
The Netherlands international scored 27 goals and created 56 chances in 34 Eredivisie matches for AZ during the 2015-16 season.
The 22-year-old had a pass accuracy of 73% and a shot accuracy of 55%, and won 21 headers, 35 dribbles and 21 tackles.