English champions Chelsea, under-fire for their threadbare Stamford Bridge pitch, will have to contend with a re-energised Ronaldinho when they host Barcelona in the Champions League on Wednesday.
The Brazilian playmaker returned from a two-game suspension at the weekend and scored twice in a 5-1 drubbing of Real Betis.
Ronaldinho netted a memorable goal in the same knockout first round at Stamford Bridge last season but Barca lost the game 4-2 to bow out.
"I've still got the images in my head of when the match finished and we were out," said the Brazilian.
Wednesday's first-leg matches also feature Ajax Amsterdam against Inter Milan, the only tie between teams that have met in the final -- the Amsterdam side triumphing 2-0 in Rotterdam in 1972.
Ajax coach Danny Blind must contend without his entire first-choice midfield, as well as influential Czech defender Zdenek Grygera and will hope Inter striker Adriano does not rediscover his scoring touch.
The Brazilian has not hit the target in his last nine games.
"I'm going through a difficult period, I can't hide the fact. But I'm not going to let it worry me too much either," he said.
Werder Bremen host Serie A leaders Juventus with midfielder Johan Micoud warning his team mates they will be up against possibly the world's best striker.
"Juventus have high class forwards, and with David Trezeguet you have in my opinion one of the best, maybe the best striker in the world," Micoud said of his fellow Frenchman.
Juve coach Fabio Capello has problems in defence with Jonathan Zebina, Gianluca Zambrotta and Giorgio Chiellini struggling to shake off injuries. Gianluca Pessotto could start on the right and Federico Balzaretti on the left.
Rangers will break new ground when they take on Villarreal at Ibrox, becoming the first Scottish side to play in the knockout stages of Europe's elite club tournament.
The Scottish champions have underperformed in the league but coach Alex McLeish, who will step down at the end of the season, believes Rangers save their best for European nights.
"It is a huge occasion, but we have faced big tasks in the Champions League and we have not been found wanting," he said.
Captain Quique Alvarez will be missing for Villarreal, who have reached the last 16 in their debut season in the Champions League.
The 30-year-old defender has a leg injury while playmaker Juan Roman Riquelme is also nursing a thigh injury, although doctors are optimistic he will be fit for the first leg.
