Union Espanola and Fluminense could become the first sides to advance to the last 16 of the Copa Libertadores 2012, as the group phase enters its seventh week. In contrast, last year’s runners-up Penarol face virtual elimination if they lose in Chile. FIFA.com looks ahead to all the midweek action in Latin America’s number one club competition.

Game of the week
Universidad de Chile (CHI) - Penarol (URU)
Group 8 – Tuesday 27 March, 21:30 (local time), Estadio Nacional, Santiago

There is plenty riding on this intriguing duel between the respective Copa Sudamericana 2011 champions and last year's beaten finalists in this competition. Languishing at the bottom of the section after collecting one point from their first three games, Los Carboneros must win to stand any realistic chance of reaching the knockout phase. Jorge Sampaoli’s side, meanwhile, are three points better off in third, having earned a valuable draw when the two sides met in Montevideo earlier this month. Victory here would take La U second, just a point adrift of group leaders Atletico Nacional.

The two other Uruguayan sides in the competition also find themselves in tricky positions, albeit with home games to look forward to this week. In Group 5, Nacional play host to bottom club Alianza Lima with only goal difference separating the two teams. A win for El Bolso will catapult them back into contention, but having lost their only game at the Parque Central so far, to Libertad in February, they can afford no further slip-ups.

Defensor Sporting’s position in Group 7 is even more parlous. Beaten 1-0 by Guadalajara in Mexico a fortnight ago, Los Violetas lie bottom of the pool and now face a rematch with Chivas in their final home match. A win over the Mexicans will take them up to second, however, behind runaway leaders Velez Sarsfield.

Staying with the Argentinian contingent, Boca Juniors and Arsenal face off again in Group 4 just two weeks after Los Xeneizes recorded a vital win in Sarandi. Boca have failed to win at the Bombonera in their last three games, a luckless run that includes both Libertadores and Clausura contests. Victory here would give them some breathing space in a section comfortably led by Fluminense, who will book a place in the knockout phase if they beat bottom club Zamora in Venezuela.

Like Flu, Chile’s Union Espanola will go through if they win this week. Los Hispanos are away at compatriots and Group 3 rivals Universidad Catolica, who are unbeaten with three straight draws but have much to do if they are to qualify.

There is a battle of former champions in Group 2, where third-placed Olimpia play host to unbeaten Flamengo in second. Victory for the Brazilians would take them above Lanus at the top of the section, while an Olimpia win would move them level on points with the Argentinians, who have played one game more. Finally, fourth meets third in Group 6 as Deportivo Tachira and Nacional of Paraguay square off, with both sides desperately in need of three points.

Player to watch
Fred (Fluminense)

Fred’s tally of two goals might not look much, but it equates to half his side’s goal count in Group 4. The 28-year-old striker proved his worth again at the weekend in scoring a brace in Flu’s 2-0 Taca Rio win at Bonsucesso, a result that moved them back into contention in the second phase of the state championship. Can the ex-Lyon man continue his rich vein of form in Venezuela?

Did you know?
No Argentinian has played in more Copa Libertadores matches than Boca Juniors coach Julio Cesar Falcioni. The former goalkeeper made 76 appearances for America de Cali and Velez Sarsfield in the competition and lies joint-12th on the all-time appearances list, along with three other players. El Emperador was a member of the unfortunate America side that lost three Libertadores finals in a row between 1985 and '87.

What they said
Mario Lepe, Universidad Catolica coach:
“We’ve been resting quite a few players and they should freshen the team up a little. The team won’t be lacking in motivation either because it’s the Copa Libertadores. We need to play the perfect game if we want to win and keep our options open because we’ve been dropping points at home, which is something we’ll need to make up for on the road.”

This week’s fixtures
Nacional (URU) - Alianza Lima (PER)
Deportivo Tachira (VEN) - Nacional (PAR)
Universidad de Chile (CHI) - Penarol (URU)

Defensor Sporting (URU) - Guadalajara (MEX)
Uiversidad Catolica (CHI) - Union Espanola (CHI)
Olimpia (PAR) - Flamengo (BRA)

Boca Juniors (ARG) - Arsenal (ARG)
Zamora (VEN) - Fluminense (BRA)