The Croatia international was signed by Lazio in July 2013 from Hajduk for a fee of 480,000 euros. The 23-year-old has a valid contract with Lazio until June 2018. In June 2016, Josip Elez was sent to HNK Rijeka on a season-long loan.
The 23-year-old has played 40 times for HNK Rijeka, scoring two goals and creating four assists in that time.
Josip Elez is considered to be one of the best defenders in Croatia.
The Croatia international has been in impressive form for Rijeka this season.
Josip Elez has represented Croatia at Under-17 and Under-19 level, winning 10 caps.
The defender has just 12 months remaining on his contract and Lazio may consider a deal in this transfer window to avoid losing him for nothing next summer.
The Croatia international is thought to perfectly fit the profile of defensive player Markus Weinzierl wants to target in the summer transfer window.
Euro Football Rumours understood that Lazio valuate their defender in the region of 5 million euros.
How strong that interest is and whether Schalke will make a summer move remains to be seen but it is certainly one worth keeping an eye on.