Alli withdrew from the Three Lions squad on Monday ahead of the game with Switzerland after picking up an injury in Saturday’s defeat to Spain.
But Southgate believes the 22-year-old will make Spurs’ Saturday lunchtime kick-off with Liverpool.
Southgate said at his press conference: “He has just had a minor strain and should be fine for his club at the weekend I would think, but tomorrow’s game will come too quickly.”
Alli played 90 minutes at Wembley on Saturday and Southgate was impressed with the Tottenham player’s contribution.
The manager added: “I thought his performance was good, in terms of his retention of the ball I thought he was improved in that area, his work without the ball has been good over the last six months with us.
“He makes critical forward runs, like everybody else we learned a lot from the game.”
Southgate, who led England to their best World Cup finish since 1990 in the summer, was keen to avoid talk of a new contract.
“We have had initial discussions as I said, that has been it,” he said.
“For me I have to focus on the job in hand. I am contracted for the next 22 months and my focus is on tomorrow night and then building this team to be as competitive as it can be.
“This summer was an incredible experience for everybody, so they are the games that everyone wants to be involved in, beyond that I don’t want to get into details because that will be a distraction ahead of the game.”
Despite their impressive summer performance, the Three Lions go into Tuesday’s game against the Swiss aiming to avoid four successive defeats for the first time in their history following losses against Croatia, Belgium and Spain.
Southgate is not concerned about that record, however.
“Not many England sides have played a World Cup semi-final and third-placed play-off so these stats can be whatever you want them to be really,” he added.
“From our point of view we don’t want to be in the habit of losing matches but to play three teams of the quality we have in the last three matches is a very rare occurrence in international football so we have to focus on our performances, and improving as a team.
“We have got to keep focused on the things we can control.”
The World Footballers’ Association along with FIFA have announced their shortlist of the best players for the 2017/18 season.
La Liga’s big three clubs – Real (11), Barca (10) and Atletico Madrid (3) – have 24 representatives on the list, which has been accumulated following the voting process conducted by 25,000 players across 65 countries.
Barca have Marc-Andre ter Stegen, Yerry Mina (now at Everton), Gerard Pique, Samuel Umtiti, Jordi Alba, Sergio Busquets, Andres Iniesta (since retired), Ivan Rakitic, Lionel Messi, Luis Suarez and Philippe Coutinho on the list.
At Madrid the candidates are Keylor Navas, Dani Carvajal, Sergio Ramos, Raphael Varane, Marcelo, Casemiro, Toni Kroos, Luka Modric; Isco, Karim Benzema and Cristiano Ronaldo, who is now at Juventus.
Surprisingly there is no Gareth Bale, who finished last season at a high level and scored two crucial goals in the Champions League final.
Thibaut Courtois is also on the list and he will do battle with his club-mate Navas.
Last season’s FIFPro World XI was: Gianluigi Buffon, Dani Alves, Ramos, Leonardo Bonucci, Marcelo, Kroos, Modric, Iniesta, Messi, Ronaldo and Neymar.
London is the venue for the announcement of the 2018 FIFPro FIFA World XI, to be held on September 24.
Below are the nominations for each category:
Gianluigi Buffon – Italy, Juventus/Paris Saint-Germain; Thibaut Courtois – Belgium, Chelsea/Real Madrid; David De Gea – Spain, Manchester United; Keylor Navas – Costa Rica, Real Madrid; Marc-Andre ter Stegen – Germany, Barcelona.
Jordi Alba – Spain, Barcelona; Dani Alves – Brazil, Paris Saint-Germain; Dani Carvajal – Spain, Real Madrid; Giorgio Chiellini – Italy, Juventus; Virgil van Dijk – Netherlands, Southampton/Liverpool; Diego Godin – Uruguay, Atletico Madrid; Mats Hummels – Germany, Bayern Munich; Joshua Kimmich – Germany, Bayern Munich; Dejan Lovren – Croatia, Liverpool; Marcelo – Brazil, Real Madrid; Yerry Mina – Colombia, Barcelona/Everton; Benjamin Pavard – France, Stuttgart; Gerard Pique – Spain, Barcelona; Sergio Ramos – Spain, Real Madrid; Thiago Silva – Brazil, Paris Saint-Germain; Kieran Trippier – England, Tottenham; Samuel Umtiti – France, Barcelona; Raphael Varane – France, Real Madrid; Sime Vrsaljko – Croatia, Atletico Madrid/Inter Milan; Kyle Walker – England, Manchester City.
Sergio Busquets – Spain, Barcelona; Casemiro – Brazil, Real Madrid; Philippe Coutinho – Brazil, Liverpool/Barcelona; Kevin De Bruyne – Belgium, Manchester City; Eden Hazard – Belgium, Chelsea; Andres Iniesta – Spain, Barcelona/Vissel Kobe; Isco – Spain, Real Madrid; N’Golo Kante – France, Chelsea; Toni Kroos – Germany, Real Madrid; Nemanja Matic – Serbia, Manchester United; Luka Modric – Croatia, Real Madrid; Paul Pogba – France, Manchester United; Ivan Rakitic – Croatia, Barcelona; David Silva – Spain, Manchester City; Arturo Vidal – Chile, Bayern Munich /Barcelona.
Karim Benzema – France, Real Madrid; Edinson Cavani – Uruguay, Paris Saint-Germain; Paulo Dybala – Argentina, Juventus; Antoine Griezmann – France, Atletico Madrid; Harry Kane – England, Tottenham; Robert Lewandowski – Poland, Bayern Munich; Romelu Lukaku – Belgium, Manchester United; Mario Mandzukic – Croatia, Juventus; Sadio Mane – Senegal, Liverpool; Kylian Mbappe – France, Paris Saint-Germain; Lionel Messi – Argentina, Barcelona; Neymar – Brazil, Paris Saint-Germain; Cristiano Ronaldo – Portugal, Real Madrid/Juventus; Mohamed Salah – Egypt, Liverpool; Luis Suarez – Uruguay, Barcelona.
The Azzurri take on the European champions in Lisbon, with Nice striker Balotelli set to miss his first game since being brought back into the fold by Mancini when he took over last May.
Lorenzo Pellegrini has also been left out along with Cagliari goalkeeper Alessio Cragno, Juventus defender Daniele Rugani and Roma midfielder Nicolo Zaniolo.
Mancini confirmed Fiorentina forward Federico Chiesa would start after the 20-year-old proved pivotal when he came on last Friday, along with goalkeeper Gianluigi Donnarumma.
Balotelli came under fire for his performance in their Nations League opener against Poland on Friday, where they were held 1-1.
The 28-year-old was substituted with a muscular problem, with Mancini conceding his fitness level was a problem.
But the former Manchester City boss defended his player from criticism.
“A player knows when he has played well or badly,” he said.
“I think Mario knows full well what his performance against Poland was like. Criticism is part of the game.
“We are only at the beginning of this journey and will change several players from the Poland game, also to look after the lads.
“We are ready and know it can be a very important match. I won’t say it’s decisive, as there are another two to go, but we are facing the reigning European champions.”
Italy have won six games to four against Portugal in previous meetings, but the Azzurri have not won a game in Lisbon in 31 years.
Mancini took charge of the national team after the four-time World Cup winners’ failure to qualify for Russia.
Balotelli has played in all four games so far under Mancini, scoring in a 2-1 friendly win over Saudi Arabia. Mancini’s other two friendlies were a 3-1 defeat to World Cup winners France and 1-1 draw with the Netherlands.
Balotelli has made the trip to Portugal with the squad as Mancini considers him to be a central figure in the team he is trying to rebuild.
Balotelli’s place could be taken by either Andrea Belotti or Ciro Immobile.