Ibrox side Glasgow Rangers signed Joey Barton from Burnley earlier this summer.
Matthaus was part of the Bayern Munich side that faced Glasgow Rangers in the group stages of the competition 17 years ago.
Liverpool are interested in signing Newcastle United midfielder Georginio Wijnaldum.
The German signed a new six-year deal with Liverpool.
France take on Portugal in tonight's Euro 2016 final at the Stade de France.
The Arsenal star suffered a nasty ankle injury while on international duty with Chile.
Ibrox side Glasgow Rangers boss Mark Warburton has signed eight players this summer.
The 25-year-old finished as the Hoops' top goalscorer in the Scottish Premiership last season.
The midfielder featured in the pre-season friendly win over Gak 1902 on Saturday.
Rangers’ Martyn Waghorn finished as the club’s top scorer last term.