Croatia captain Luka Modric believes England counterpart and former Tottenham team-mate Harry Kane can still improve despite already being among the world's best strikers.

Kane has firmly established himself as a top marksman since debuting for Spurs in Modric's final season at the club.

The 25-year-old claimed the Golden Boot at the World Cup and has netted more than 20 goals in each of the past four Premier League campaigns.

While some observers claim burnout is beginning to reduce his effectiveness, Modric is confident Kane still has new levels to unlock.

"He's scoring a lot in recent years, playing great and practically putting Tottenham in the title race, which is a big thing considering other clubs are spending a lot of money," Modric said.

"He's already one of the best forwards in the world. If he continues to develop on the same path he can be even better."

Modric and Kane are in line to lead their countries in a behind-closed-doors Nations League clash in Rijeka on Friday.

It will be their first meeting since Croatia recovered from an early deficit to prevail in extra-time of the World Cup semi-final.

The Real Madrid midfielder cited a sense of media disrespect as motivation in the immediate aftermath of that game and he reiterated the same view in Thursday's pre-match news conference.

"It was my feeling. I didn't think the [England] players and head coach underestimated us but the people that surround their national team - commentators, journalists, fans," he said.

"We felt they disrespected Croatia. They didn't show enough appreciation and it gave us extra motivation."