Midfielders
One of the defensive-midfield spots is occupied by Eric Dier. The 24-year-old is a versatile player that can play in the midfield or as a centre-back and even as a right-back. Southgate would be willing to make use of his abilities in the defensive midfield spot.
Apart from a decent 86% pass completion rate, Dier also has made 35 interceptions in the League. He surely knows how to break the opposition's play and maintain the momentum of the game for his side.
Now we have Adam Lallana in the midfield role besides Dier. He has played only seven games in the league so far and created eight chances. Southgate would be trusting Adam in the midfield because of the experience and physicality he brings to the team.
Jordan Henderson or Harry Winks can be the alternatives.
In the attacking midfield role, we have Dele Alli. This player is one of the best young talents in the world right now and he rightly deserves his first-team spot. Alli has been instrumental for Spurs this season. He already has five goals and seven assists to his name.
Apart from this, he has created a massive number of chances for his side in the league, 52 chances to be precise. Alli surely lacks some experience but Southgate knows that he is the best man for the job. Ross Barkley can be the substitute player in this position.