Fernando Santos's side recorded a 3-2 win over Ghana in their tournament opener on Thursday night, while Uruguay played out a goalless draw with South Korea earlier in the day.
Match preview
Cristiano Ronaldo became the first men's player to score in five World Cups when he found the back of the net from the penalty spot against Ghana on Thursday evening.
Portugal were 3-1 ahead in Doha until the latter stages, but Osman Bukari made it 3-2 before Inaki Williams passed up a huge chance to level in the final moments, with the Athletic Bilbao forward slipping in front of goal after he had cleverly taken the ball away from Diogo Costa inside the penalty box.
Santos's side survived to claim a huge three points, and another victory on Monday would put them into the knockout round of the competition ahead of their final game in the section against South Korea on December 2.
A Selecao, who have not been past the last-16 stage of a World Cup since 2006, would take on the runner-up in Group G in the next round if they did finish at the top of this section, which could be Brazil, Switzerland, Cameroon or Serbia.
Uruguay and Portugal actually locked horns in the round of 16 in Russia four years ago, with the South American nation running out 2-1 winners courtesy of a double from Edinson Cavani.
The Navigators are not seen as one of the favourites to triumph in Qatar, but it would be some story if Ronaldo could captain this side to World Cup success considering how the last few weeks have unfolded for the 37-year-old.
Uruguay twice hit the woodwork in their tournament opener with South Korea on Thursday, with Diego Godin heading against the post in the first half before Federico Valverde thumped one onto the woodwork in the latter stages of what proved to be a goalless draw.
Diego Alonso's side can neither qualify nor be eliminated on matchday two, but a poor result would certainly leave them vulnerable ahead of their final match in the section against Ghana on December 2.
Uruguay have won the World Cup on two occasions - 1930 and 1950 - while they have made a positive impression in their last three tournaments, finishing fourth in 2010, reaching the round of 16 in 2014 and progressing to the quarter-finals four years ago in Russia.
La Celeste have plenty of experience when it comes to reaching the latter stages of a World Cup, and they will still fancy their chances of progressing through this group despite only drawing their opener.
The South American nation have only ever faced Portugal on three occasions, with their last meeting, as mentioned, coming in the last-16 stage of the World Cup.
Uruguay have again turned to their experienced players in Qatar, but it remains to be seen whether the likes of Godin, Martin Caceres, Cavani and Luis Suarez can help the team navigate their way into the round of 16.
Portugal World Cup form:
W
Portugal form (all competitions):
W
L
W
L
W
W
Uruguay World Cup form:
D
Uruguay form (all competitions):
W
D
W
L
W
D
Team News
Portugal have not reported any injury concerns from their clash with Ghana, but head coach Santos could make a change from the side that took to the field last time out.
Indeed, the European nation had greater control when William Carvalho was introduced early in the second period, and the midfielder could now take the place of Otavio in the starting side.
Rafael Leao scored off the bench against Ghana but is likely to be among the substitutes again, with Bruno Fernandes and Joao Felix set to support Ronaldo in the final third of the field.
Santos has the option of bringing in Diogo Dalot and moving Joao Cancelo across to left-back, but Raphael Guerreiro is expected to keep his spot for the team's second match of the competition.
As for Uruguay, Ronald Araujo's fitness has been a controversial topic, with the centre-back included in the squad despite undergoing thigh surgery at the end of September.
The Barcelona defender is again expected to miss out here, so Caceres should join Godin, Jose Gimenez and Mathias Olivera at the back, with Matias Vecino featuring alongside Valverde and Rodrigo Bentancur in midfield.
Cavani is the obvious option to come into the XI, but Suarez is again expected to get the nod from the start, with Darwin Nunez and Facundo Pellistri playing in the wide areas.
Suarez did find it difficult against South Korea, though, so the 35-year-old's fitness will need to be assessed before it is decided whether he will again be in the XI for this contest.
Portugal possible starting lineup:
Costa; Cancelo, Dias, Danilo, Guerreiro; Bernardo, Neves, Carvalho; Fernandes, Ronaldo, Felix
Uruguay possible starting lineup:
Pochet; Caceres, Godin, Gimenez, Olivera; Valverde, Bentancur, Vecino; Pellistri, Suarez, Nunez
We say: Portugal 2-1 Uruguay
Portugal were defensively vulnerable against Ghana, but their quality in the final third allowed them to pick up a huge three points. Uruguay, on the other hand, found it difficult to create openings against South Korea. Monday's contest should be a close match, but we believe that Portugal will have enough to triumph in order to book their spot in the knockout round of the competition with a match spare.