Sergio Conceicao's side, who kicked off their cup title defence with an emphatic 6-0 thrashing of Anadia on October 16, are unbeaten in six straight away games and will look to keep the ball rolling.
Match preview
Mafra put on a fine show of fighting spirit as they fought back from behind to claim a 3-2 home victory over Covilha when the sides met in the Segunda Liga last Friday.
Mohammed Adams and Diogo Rodrigues scored to cancel out Diogo Almeida's 15th-minute opener and hand the visitors a first-half lead, but Pedro Pacheco restored parity three minutes into the second period before Almeida grabbed his second of the game to complete the comeback.
Prior to that, Mafra ended their run of second consecutive games without a win on October 29, when they picked up a slender 1-0 victory at Torreense courtesy of a dramatic stoppage-time winner from Loide Augusto.
Having managed just three points from their previous seven matches, back-to-back victories over Torreense and Covilha has seen them rise to 12th place in the Segunda Liga standings, level on 15 points with 11th-placed Penafiel.
Ricardo Sousa's men will now look to carry on their new-found form into the Taca de Portugal, where they secured a third-round 4-2 victory over Primeira Liga side Maritimo two weeks after beating UD Santarem in their cup opener on October 2.
Porto, on the other hand, returned to winning ways in the Primeira Liga as they comfortably saw off Pacos de Ferreira 4-0 at the Estadio do Dragao on Saturday.
Off the back of a 2-1 victory over Atletico Madrid which saw them secure top spot in Group B of the Champions League, a brace from Evanilson and Mehdi Taremi's 31st-minute strike put the visitors three goals down heading into the interval before Juan Delgado scored a 55th-minute own goal.
Prior to that, Conceicao's side were on a two-game winless run in the league, losing 1-0 against high-flying Benfica on October 21 — which saw their five-game unbeaten run come to an end — before being held to a somewhat disappointing draw by Santa Clara one week later.
Porto, who are currently second in the Primeira Liga standings with 26 points from 12 games, now turn their attention to the Taca de Portugal, where they secured their 18th title courtesy of a 3-1 victory over Tondela in last season's final on May 22.
The Dragoes will be looking to pick up where they dropped off in October's cup opener, when they cruised to an emphatic 6-0 victory over third-tier outfit Anadia at the Estadio Municipal Engenheiro Silvio Henriques Cerveira.
Mafra Taca de Portugal form:
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Porto Taca de Portugal form:
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Team News
Mafra take on Portuguese champions Porto in what will be their biggest test so far this season and we expect Sousa to name his strongest possible starting side on Tuesday.
At the defensive end of the pitch, we expect an unchanged back three of Joao Goulart, Ousmane Diomande and Pedro Pacheco, who started both victories over Torreense and Covilha.
Guilherme, Leandrinho, Leo Cordeiro and Enca Fati should retain their roles at the centre of the park, while Pedro Lucas and Lucas Rodrigues should form the attacking duo once again.
Almeida, who has started just two Segunda Liga games this season, turned in an eye-catching display against Covilha and we expect the former Benfica man to be rewarded with a place in the XI on Tuesday.
Meanwhile, Porto will be without the services of veteran defender Pepe, who has been sidelined since picking up an ankle injury in the Champions League game against Bayer Leverkusen on October 4.
Brazilian youngster Gabriel Veron has missed the last three matches after coming off injured against Club Brugge on October 26 and the 20-year-old is out of contention for the trip to the Estadio Municipal de Mafra.
We expect Conceicao to make several changes to the side that started Saturday's victory over Pacos de Ferreira, with Bruno Costa and David Carmo potentially pairing at the heart of the defence, while 25-year-old Toni Martinez will push for a starting role in attack.
Mafra possible starting lineup:
Dida; Goulart, Diomande, Pacheco; Fati, Leandrinho, Cordeiro, Guilherme; Almeida, Lucas, Rodrigues
Porto possible starting lineup:
Costa; Pepe, Costa, Carmo, Sanusi; Otavio, Costa, Eustaquio, Galeno; Evanilson, Martinez
We say: Mafra 0-3 Porto
Mafra have put together a fine run of form in recent weeks and will look to cause an upset on Tuesday. However, given the gulf in quality and experience between the two sides, we are backing a rotated Porto side to claim a comfortable victory.