Reigning champions Liga de Quito begin the defence of their crown this Tuesday, with the visit of Brazilian giants Palmeiras to the Ecuadorian capital. The fixture kicks off during a week in which no fewer than eight former Libertadores champions are in action. Once again, is on hand to preview a busy programme in South America's premier club competition.

Game of the week
Liga de Quito-Palmeiras
Tuesday 17 February Estadio Casa Blanca (Quito), 17:00 (local time)

The old maxim that says it is harder to stay at the top than to get there is one which Liga de Quito will soon be able to identify with. As surprise winners of last year's edition, the Ecuadorian side will be under pressure right from the off this year, with their first test provided by Palmeiras. The 1999 champions will enter the game in upbeat mood following their comfortable preliminary-round win over Real Potosi, and they can count on the vast experience of Edmilson and scoring prowess of Keirrison. However, the visitors will not have it easy at the Casa Blanca, where Jorge Fossati's side are on a 14-game unbeaten run in this competition, stretching back to 2005.

Winners of four of the last nine editions of the tournament, Boca Juniors have a squad brimming with experience as they prepare for their Group 2 opener at home to Ecuador's Deportivo Cuenca. Captained by Juan Roman Riquelme, Los Xeneizes will be counting on the same nucleus of players as last year when they reached the semi-finals. As serious contenders for the title once again, the Buenos Aires giants know that anything less than a winning start would be a major upset.

Sao Paulo, champions in 2005 and runners-up the following year, get their campaign underway this Wednesday in Group 4, and they will be without inspirational goalkeeper Rogerio Ceni for the visit of the ever-dangerous Independiente Medellin.

Brazil is also the venue for another meeting of former champions, that of Cruzeiro and Estudiantes, both of whom will be getting their first taste of action in Group 5. If recent form is any guide, then the team from Belo Horizonte should have the edge, having beaten city rivls Atletico Mineiro in the Minas Gerais derby at the weekend. El Pincha, by contrast, have just one point after two games in the Argentinian Clausura.

The other two sides in action this week who have tasted Libertadores glory are Uruguay's Nacional and Colo Colo of Chile. El Bolso, whose confidence should be high after winning their Apertura championship on Sunday, will be hoping to make it two wins from two in Group 3 when they take on their namesakes from Paraguay - themselves under pressure after losing their opener last week. El Cacique, meanwhile, will be hoping to extend their fine recent form at home when they welcome Brazil's Sport for their Group 1 opener.

Rounding off this week's programme is Universitario of Peru against San Lorenzo, the latter having won their opening Group 8 fixture last week against San Luis, and the visit of Caracas to Chile's Everton for the pair's debut in Group 6.

Player to watch
Martin Palermo (Boca Juniors)
After a six-month lay-off due to injury, the 35-year-old striker will be aiming to find his range once more in a tournament in which he seems to thrive. In the four editions he has competed in to date, the Argentinian has already racked up 18 goals, so Xeneize fans will be hoping Carlos Ischia judges him fit for a run-out tonight.

The stat
- The number of times Sao Paulo and Palmeiras have participated in the Copa Libertadores, making them the Brazilian clubs with the most appearances in the competition's 50-year history.

What they said
"It's not every day you face Boca. Given the calibre of our opponents, we know it's going to be a tough assignment, but I have confidence in my players," Deportivo Cuenca coach Guillermo Duro.

This week's fixtures
Tuesday 17
Liga de Quito (ECU) - Palmeiras (BRA)
Boca Juniors (ARG) - Deportivo Cuenca (ECU)
Everton (CHI) - Caracas (VEN)

Wednesday 18
Nacional (PAR) - Nacional (URU)
Sao Paulo (BRA) - Independiente Medellin (COL)
Colo Colo (CHI) - Sport (BRA)

Thursday 19
Cruzeiro (BRA) - Estudiantes (ARG)
Universitario (PER) - San Lorenzo (ARG)