Beaten by Bologna last time out, Inter's deficit to distant league leaders Napoli grew further, and their main concern now is cementing a top-four finish. Their visitors, meanwhile, lost their first game in four but remain on course to achieve their objective of survival.
Match preview
For all their progress in Europe and the Coppa Italia, Inter's league campaign has been a tale of two halves, as they have won 10 of their 12 home fixtures - conceding only six goals - while their away record is barely better than Lecce's.
The Nerazzurri have now lost seven of their first 24 Serie A matches for the first time since the 2016-17 season - when they went on to finish seventh - after a drab display in last Sunday's loss to Bologna.
While an off-field battle rages with city rivals Milan about the clubs' future away from the iconic San Siro, they entered the weekend level on points with the Scudetto-holders - both far adrift of champions-elect Napoli.
There remains plenty to play for, though, as Simone Inzaghi's side must complete a half-done job against Porto if they are to reach the Champions League quarter-finals, with a two-legged Coppa semi versus old foes Juventus lying further around the corner.
Home form will surely play its part if Inter are to lift more silverware this season - having already secured the Supercoppa Italiana - as not only did they become the first team to topple Napoli in the league at San Siro, but just two clubs have conceded fewer goals at home throughout Europe's top five leagues.
All of which makes them strong favourites to resume winning ways on Sunday evening, as they have lost only one of their last 13 Serie A matches against Lecce, and none since 2012.
Also beaten 2-1 at home in August's reverse fixture, Lecce have lost each of their last eight league meetings with Inter in Milan, conceding an average of 2.5 goals per game.
Marco Baroni's men have fared far better on the road in recent weeks, though, as after victories at Cremonese and Atalanta, Lecce can now win three away games in a row for just the second time in their top-flight history.
All told, they have lost only one of their last four games, including a 1-1 draw with Roma, but last week's defeat at home to Sassuolo put a dampener on dreams of mounting an assault on Serie A's top 10.
Having scored twice in both Cremona and Bergamo, the Salentini could not find the net against one of the league's worst defensive sides; conceding a header for the seventh time this season - the second-highest such tally in Serie A.
Nevertheless, last year's Serie B champions are still well set to retain their top-tier status come June, when stars of their comeback campaign such as midfielder Morten Hjulmand - captain aged just 23 - and top scorer Gabriel Strefezza may be picked off by clubs higher up Calcio's pecking order.
Inter Milan Serie A form:
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W
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D
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Inter Milan form (all competitions):
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Lecce Serie A form:
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Team News
Keeping in mind a busy schedule ahead this month, Simone Inzaghi may be loath to rush back either Milan Skriniar or Federico Dimarco from injury, after both trained individually earlier this week. A back problem ruled Skriniar out against Bologna last week, while Dimarco was sidelined by a muscular issue.
After starting on the bench at Dall'Ara, Nicolo Barella should be brought back into Inter's starting XI, while there remains a three-way tussle for two spots up front.
Romelu Lukaku - scorer of two goals in three league games against Lecce - has netted 49 times for Inter in Serie A and could become the fourth player to score at least 50 goals in both the Premier League and Serie A, after Gianfranco Zola, Cristiano Ronaldo and teammate Edin Dzeko.
The latter has scored twice in 13 appearances during 2023, after bagging seven goals in his last 13 games of 2022. He remains in contention, though, to partner Lautaro Martinez in attack.
While 'El Toro' has the most goals for Inter this term, Brazilian winger Gabriel Strefezza has carried the can for Lecce, finding the net seven times during his second Serie A season.
Assan Ceesay made little impact as the Giallorossi's central striker against Sassuolo, so Milan loanee Lorenzo Colombo could start instead at San Siro, seeking his fifth league goal this season.
In fact, Marco Baroni has plenty of available options to complete his front three as Federico Di Francesco returns from a one-match ban, but defensive trio Kastriot Dermaku (hernia), Marin Pongracic (ankle) and Federico Baschirotto (suspension) are all ruled out. Samuel Umtiti should replace the latter.
Inter Milan possible starting lineup:
Onana; Darmian, Acerbi, Bastoni; Dumfries, Barella, Brozovic, Calhanoglu, Gosens; Martinez, Lukaku
Lecce possible starting lineup:
Falcone; Gendrey, Umtiti, Tuia, Gallo; Blin, Hjulmand, Maleh; Strefezza, Colombo, Di Francesco