Although Messi won the Spanish league title with Barca last season, the 31-year-old had an unhappy World Cup, missing a penalty against Iceland and scoring only once in four games as they were knocked out in the last 16.
Messi, who last failed to make the final three nominees in 2006, has won the award, in its various guises, five times and finished runner-up on another six occasions.
Ronaldo helped Real Madrid claim a third consecutive Champions League crown before securing a transfer to Juventus.
Midfielder Modric, also part of Madrid's Champions League triumph, finished as a runner-up with Croatia at the World Cup, winning the best player award at the tournament in Russia.
Egyptian forward Salah scored 44 goals for Liverpool last season, helping the English club reach the Champions League final where they were beaten by Real.
Hampered by injury, he made little impact at the World Cup as his country went out in the group stage.
Brazil's Kaka, in 2007, was the last player other than Ronaldo or Messi to win the award.
France's World Cup-winning captain Hugo Lloris is in contention for the goalkeeper of the year award, alongside Golden Glove winner Thibaut Courtois of Belgium and Denmark's Kasper Schmeichel.
Former Real Madrid manager Zinedine Zidane, France coach Didier Deschamps and Croatia's Zlatko Dalic were on the shortlist for the coach of the year award.
The women's player of the year award is between Olympique Lyonnais duo Ada Hegerberg and Dzsenifer Marozsan, who had an unbeaten league season and lifted the Women's Champions League, and Brazil's triumphant Copa America Femenina captain Marta.
The awards ceremony will take place in London on Sept. 24.
(Reporting by Hardik Vyas in Bengaluru; additional reporting by Brian Homewood; Editing by Alison Williams and Ken Ferris)
