Alli missed the last three games of the season for Spurs due to suspension following a clash with Claudio Yaboc so he will be well rested for the game against Turkey.
England head coach Roy Hodgson revealed that he has been impressed with Wilshere and Henderson in training but made no guarantees that both would be used.
“The mere fact Henderson is in contention is an enormous bonus because when the injury occurred, we were told to work on the basis that it would keep him out of the Euros because it would take a longer recovery time,” Hodgson said.
“He, alongside Jack (Wilshere), are the reasons we have extended our squad from the usual 23 to 26 because we do need to assess them.
“We do need to be sure that if we are going to select them, they will be the Jordan Henderson and the Jack Wilshere that we know and not players that are recovering to be that player again.
“We have to be satisfied with them. An international tournament puts an awful of demand on a player physically.”
England have never lost an international game against Turkey or conceded a single goal but the Crescent-Stars are unbeaten in their last 14 games.
Turkey did draw their last game against England 0-0 and booked a place in the European Championships this summer after knocking the Netherlands out of the competition.