Paris Saint-Germain midfielder Lucas Moura believes fellow Brazilian Willian will carry the major threat for Chelsea in the second leg of their Champions League last-16 encounter.
The familiar Ligue 1 and Premier League foes resume hostilities at Stamford Bridge on Wednesday, with PSG holding a slender 2-1 advantage from the initial encounter in the French capital.
Chelsea have been revitalised by veteran Dutch coach Guus Hiddink following a shambolic start to their Premier League title defence under Jose Mourinho last year, but excellent performances from Willian have provided one of the few constants of their campaign.
The former Shakhtar Donetsk winger has 10 goals in 40 appearances across all competitions, including a phenomenal five from seven in the Champions League.
"Willian is maxed out. For me is the best player of Chelsea at the moment, so we have to watch him closely," Lucas told reporters following the runaway Ligue 1 leaders' 0-0 draw against Montpellier.
"But there are other talents at Chelsea as [Eden] Hazard, [Cesc] Fabregas or Pedro, so defensively we cannot focus on a single player.
"Everyone knows that Wednesday is the match everyone is waiting for. It's the most important game of the season for us."
John Obi Mikel's away goal for Chelsea could still prove pivotal in the tie and Lucas is keen for Laurent Blanc's talented attacking line-up to make their presence felt in London.
"Everyone knows the importance of an away goal," he added. "We must think only about winning."
For his part, Willian told Telefoot that PSG's Italian midfielders Thiago Motta and Marco Verratti could be influential in a finely poised tie.
"They can win but we can also, it's 50-50 for me," he said. "Two players are essential to Paris - Motta and Verratti.They control the ball and control the game"