Japan manager Vahid Halilhodzic said he is watching the progress of the players from the Under-23 side closely as he returned from his two months scouting tour in Europe on Friday.
The U-23s booked their place in this summer's Rio de Janeiro Olympics last month by winning the Asian U-23 Championship, and Halilhodzic was eager to add new blood to his side.
"Everyone in the young generation is in line for a call-up if they play well," Halilhodzic said. "There are several interesting players."
Only notable name that features for both sides to date is new Urawa Reds midfield-signing Wataru Endo, who captains the U-23 side.
The 63-year-old manager claimed conversations were meaningful after seeing Europe-based players including AC Milan's Keisuke Honda, who scored his first goal of the season this month, and Schalke side-back Atsuto Uchida who has been ruled out since last March.
"It was more of listening to their stories properly than me speaking to them," Halilhodzic said. "We had constructive exchanges of opinions."
He will attend openers of the new J. League campaign this weekend and will hold a camp for the national side between March 7 and 9.