Southgate started with three centre-backs in the 1-0 win over Netherlands on Friday evening, with Kyle Walker starting in central defence in what was an unexpected move.
England, whose unbeaten run stretched to seven games, have also kept a clean sheet in each of their last five internationals, going 537 minutes without conceding.
Guillem Balague insists England must stick with Gareth Southgate even if they fail at this summers World Cup in Russia
"What weve got to do is allow this young team to perform," Southgate said. "Theres some super-exciting young players. The reason there has been a disconnect with the team is not because of what theyve done. Its because of what teams I played in did and historic stuff.
"Weve got to give them the freedom to grow and improve and learn together. They dont have 50, 100 caps [each]. Theres still years ahead of them as a group and they can get better and better."
Italy have failed to score in their last three internationals, and lost 2-0 against Argentina in Manchester on Friday evening.
The Azzurri, who have four world titles, will not be going to this summers World Cup, the first time they have failed to qualify for the competition since 1958.
Arsenal midfielder Jack Wilshere will not return to the England squad after picking up a minor knee injury, but Southgate said he may be back for Arsenals clash with Stoke at the weekend in the Premier League.
Jack Butland will start for England against Italy in Tuesdays international friendly
Liverpools Joe Gomez withdrew from the squad on Sunday due to injury, while Ryan Bertrand is also ruled out. Leicester defender Harry Maguire will face a fitness test.
Southgate also said he is yet to decide who will captain England.
Luigi Di Biagio is also likely to make some changes to the Italy side that lost against Argentina, but Giorgio Chiellini remains sidelined.
