Goalkeeper Hart, who has spent the 2017-18 season on loan at West Ham United, is expected to be replaced by Burnley's Nick Pope. Meanwhile, Arsenal playmaker Wilshere could be overlooked in favour of versatile Manchester City man Fabian Delph.
Wilshere hasn't started for the Three Lions since UEFA Euro 2016. However, the oft-injured schemer has impressed at times for Arsenal this season, contributing two goals and five assists in 33 matches (24 starts).
Taylor and Fifield said a shaky fitness record might have been the decisive factor in Wilshere not making the trip to Russia. However, not everybody is convinced.
Uche Amako of the Daily Express poured cold water on the theory, while also pointing out Southgate has picked other players with fewer minutes this season:
Southampton legend and Sky Sports Football pundit Matt Le Tissier also felt Wilshere should be involved:
Leaving Wilshere out means Southgate will leave behind one of his nation's most technically gifted midfielders. Wilshere's eye for a pass, combined with the ability to dribble the ball past markers, makes him a potential match-winner in the final third.
Even so, Southgate may believe he has enough creative talents with Tottenham Hotspur's Dele Alli, Liverpool's Adam Lallana and Manchester United's Jesse Lingard all available for selection.
What is more surprising is Delph getting the nod ahead of Wilshere, despite the 28-year-old enjoying success with runaway Premier League champions City. Delph became useful to the Citizens when he converted to left-back to cover the injury suffered by Benjamin Mendy.
If taking a player as flexible as Delph is a safe choice by Southgate, shunning Hart is the opposite. Taylor and Fifield noted how "Southgate has chosen to ignore his most experienced player," with Hart appearing in four major tournaments previously.
While Pope is an admirable replacement, John Cross of the Daily Mirror expressed sympathy for the 31-year-old:
Southgate's decisions will find detractors and admirers in equal measure. What is clear, though, is how the former Aston Villa and Middlesbrough centre-back isn't afraid to ditch some of the big names available and give new faces a chance to end England's dismal run on the international stage.