Iheanacho played as a substitute in Saturday's 0-0 draw at Fleetwood Town.
Besiktas have also been linked with Iheanacho's Leicester City teammate Islam Slimani, as the search for Tosun's replacement continues.
In a chat with Daily Trust yesterday, the member of the NFF technical committee said he completely agrees with the coach because World Cup is not a tea party and so only players who are playing regular football should be considered.
"It was a possibility for him to have another game or so, because he hasn't played a lot, because of the injury to Jamie".
A former worldwide, Garba Lawal has supported the recent call by the coach of the Super Eagles, Gernot Rohr for Ahmed Musa and Kelechi Iheanacho to change club, if they are to stand any chance of playing for Nigeria at the 2018 World Cup.
Southampton fans were quick to have their say on the Nigerian via social media, and while one said he is "just the sort of player we need", another said "if we're going to spend £20m on someone I'd rather it was him than Walcott".