By Gabriel Pessoa

The group stage of the 2019 Copa Libertadores is halfway done. High-Flying underdogs such as Cerro Porteno, San Lorenzo and Athletico Paranaense have three matches left to defend their positions atop their respective groups. Tournament favorites who may have slipped along the way, like River Plate, Flamengo and Boca Juniors, are running out of time to make up for their disappointing results.

Matchday four sees return legs begin this week across the beIN SPORTS network. Portuguese commentary will now be available on all games involving Brazilian clubs, via SAP on beIN SPORTS. Here are five matches to watch:

Penarol (URU) vs. LDU Quito (ECU) – Group D

Tuesday, 8:20pm ET live on beIN SPORTS (ENG HD)

One of the eye-catching scores of this past week came courtesy of Uruguayan side Penarol. The bright lights of Maracanã Stadium did not intimidate the ‘Carboneros’ as they defeated Flamengo 1-0 in Rio de Janeiro. The win propelled Penarol to the top of group D.

The five-time Copa Libertadores champion Uruguayan side will look to defend that top spot on Tuesday as it plays host to third-place LDU Quito. This match has huge stakes as two points are all that stand between the two sides. A win from LDU Quito would send them top and certainly make things interesting, to say the least.

Gremio (BRA) vs. Rosario Central (ARG) – Group H

Wednesday, 8:15pm ET live on beIN SPORTS Connect 8

This Libertadores campaign has certainly not gone Gremio’s way. The 2017 champions have only managed to accumulate one single point after three matches. On the flip side, Paraguayan club, Libertad have been able to fight through three rounds of qualification, overcome a scandalous coaching change and go undefeated in Group H to push Gremio into third place.

Renato Gaucho’s men will have the chance to begin their road to redemption at home against last-place Rosario Central on Wednesday. Sparks flew the last time these two sides met, although it ended in a draw we were provided a back and forth match that came down until the final whistle.

Rosario Central also has just one point to its name. A loss for either side could very well mean the end of their hopes of qualifying out of this group.

Boca Juniors (ARG) vs. Jorge Wilstermann (BOL) – Group G

Wednesday, 8:20pm ET live on beIÑ SPORTS (SPA HD)

Group G is completely up for grabs. Athletico Paranaense sits in first place but with a mere four-point lead on fourth place Jorge Wilstermann.

The Bolivian club will have a huge road test ahead of itself on Wednesday as it travels to Buenos Aires to face none other than Boca Juniors. La Bombonera will be the stage for Wednesday’s clash. Last year’s runner-up will look to pull out a win as it begins its attempt to claw its way back to Libertadores glory.

Although the recent results have been disappointing for Boca Juniors, it may be too soon to hit the panic button just yet. A loss, win and tie still has the Argentine club in second place. A victory for Boca should set the club back on course in Group G.

River Plate (ARG) vs. Alianza Lima (PER) – Group A

Thursday, 5:50pm ET live on beIN SPORTS (ENG HD)

Since winning the Libertadores last winter, River Plate has struggled to live up to its billing as South American champion.

The Argentinian club has drawn all three of its group A matches and lost playmaker Juan Fernando Quintero to a serious knee injury. However, last week’s draw may have been a slight silver lining. Marcelo Gallardo’s men went to Porto Alegre, Brazil and pulled out a relatively favorable result against a difficult opponent in Internacional.

River will look to build on that draw at home against fourth-place Alianza Lima this week. Depending on the other result in the group, a win could send River Plate to second in the group despite all their previous struggles.

Flamengo (BRA) vs. CD San Jose (BOL) – Group D

Thursday, 7:55pm ET live on beIN SPORTS (ENG HD)

Flamengo fell to second in group D after a home loss to Penarol last week at the Maracanã. That loss included Gabriel ‘Gabigol’ Barbosa picking up a red card which will mean he’s not available for the ‘rubro-negro’ Thursday night against San Jose.

‘Gabigol’ has been instrumental for the club from Rio de Janeiro and scored the winning goal last time these clubs met.

Look for Diego and Everton Ribeiro to step their game up and lead Flamengo at home against the Bolivian club that currently sits in last place with just one point.