The hosts have won just one of their last four games in the top flight, while Sporting have registered six consecutive league victories, seeing them move 10 points clear of Saturday's opponents.
Porto got back to winning ways in league action last time out when they won late against basement side Maritimo.
The Dragoes looked set to play out a fourth consecutive Primeira Liga draw, with the game at 1-1 after Mateus Uribe put Porto ahead early on, before they were awarded a penalty deep into added time, which Otavio made no mistake in converting.
Before that, Sergio Conceicao's side were held to draws with Belenenses, Braga and Boavista, seeing them lose ground on Sporting at the top of the table.
However, they will take plenty of positives from their recent win in continental action, when they defeated Juventus 2-1 in the first leg of their Champions League round-of-16 tie.
They had the perfect start, when Mehdi Taremi put Conceicao's side ahead after just two minutes, and they enjoyed a similar start to the second half when Moussa Marega doubled that lead soon after half time, before Federico Chiesa added an away goal for the Italian outfit late in the game.
The defending champions boast the Primeira Liga's best attack this campaign, with no side in the division matching the 45 goals they have scored from 20 games.
That will definitely encourage Conceicao and his side, as they come into this game needing to win in order to keep their hopes alive of retaining the league title that they won last season.
However, they come up against a Sporting Lisbon side in formidable form, who look to be storming towards the trophy.
In his second season managing in the Portuguese top flight, Ruben Amorim has the side from the capital well on track to win their first Primeira Liga title since 2002.
They remain without a loss in league action this season, having picked up 54 points out of a possible 60 at this stage of the campaign.
A lot of that is down to their strong defence, with no side in the division shipping as few as the 10 goals they have conceded from 20 matches in the top flight.
However, their attack is not to be scoffed at either, with only Saturday's opponents topping their 42 goals scored.
As a result of their strong run of form, Os Verde e Brancos now have a comfortable lead over Porto in the table, and an away win on Saturday would stretch that gap to 13 points with 13 matches to go in the league.
Porto Primeira Liga form: DDDDWW
Porto form (all competitions): WWDDDW
Sporting Lisbon Primeira Liga form: WWWWWW
Porto should have a full squad to pick from for this crucial encounter, other than centre-back Ivan Marcano, who remains out with a ligament rupture.
The dangerous pairing of Mehdi Taremi and Moussa Marega will pair up in attack once again for the Dragoes, having both scored in the Champions League win over Juventus.
Sporting Lisbon will be without forward Paulinho, who is out with a hamstring injury after joining the club in January from Braga.
In his absence, 18-year-old Tiago Tomas is expected to start in the central role, having impressed as part of the front three in his first season in the top flight.
He will be supported by Pedro Goncalves, who tops the Primeira Liga scoring charts with 14 goals in his first season in the capital.
Porto possible starting lineup:
Marchesin; Manafa, Pepe, Mbemba, Sanusi; Corona, Uribe, Oliveira, Diaz; Taremi, Marega
Sporting Lisbon possible starting lineup:
Adan; Inacio, Coates, Feddal; Porro, Mario, Palhinha, Mendes; Goncalves, Tomas, Santos
We say: Porto 1-1 Sporting Lisbon
We see this game being a fairly cagey affair, with neither side, especially Porto, willing to lose the match.
With the league's best defence squaring off against its best attack, we can see the teams cancelling each other out, resulting in a draw which suits the league leaders much more than the defending champions.