Former Bayern Munich boss Kovac will be allowed to invest in new players thanks to Russian investor Dmitry Rybolovlev.
And according to SPORT BILD, he has started planning for next season with sporting director Paul Mitchell by pitching two names.
Jovic, 22, cost Real Madrid a €60m fee but has has scored just two goals in 26 appearances this term.
Both Jovic and Kostic are Serbian internationals and Kovac trained Jovic during his days at Frankfurt.
Kovac has replaced Robert Moreno at Monaco and hopes to propel the principality club, who finished ninth this season.