Massimo Pinca/Associated Press

Juventus centre-back Giorgio Chiellini has offered tips on how to defend against Lionel Messi and Cristiano Ronaldo, although his advice for stopping the Argentinian summed up how helpless defenders feel when they face Barcelona's main man.

Chiellini explained it is a vital component of modern-day defending to know exactly what you're coming up against, before turning his views to the world's best duo, per Eurosport Italia (via Josep Capdevila in Sport):

In the last few years the role of the defender has been re-evaluated. Everyone has to be good at understanding their role. Experience helps you to read certain situations better and make less mistakes in terms of behaviour. Knowledge of the opponent is essential, too, individually as well as the team. How do you mark Cristiano Ronaldo? You try not to leave him alone, don’t let him shoot on his right foot. And Lionel Messi? Just make the sign of the cross.

Juve faced both Ronaldo and Messi last season as the Old Lady claimed the runners-up spot in the UEFA Champions League, beating Real Madrid over two legs at the semi-final stage before losing to Barcelona in the final—a match Chiellini missed through injury.

The Italian bemoaned the missed chances his team had in the Berlin showpiece, which Juve eventually lost 3-1 through goals from Luis Suarez and Neymar after Alvaro Morata had cancelled out Ivan Rakitic's opener for Barca, per Capdevila's report: "We could have won it because we had chances. When the game finished we knew we could’ve done better. If we have another opportunity we’ll arrive better prepared."

Juventus have to get past Bayern Munich in their last-16 second leg next week if they are to keep the dream alive of redeeming themselves and winning the Champions League this season.

The tie is in the balance after a 2-2 draw in the first leg at the Juventus Stadium, although Bayern remain the favourites to advance because of their away goals, per Bleacher Report's Sam Tighe:

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While Bayern can't boast either Messi or Ronaldo in their side, they do have a number of superstars who could cause Juve's defence some serious problems, not least Robert Lewandowski and Thomas Muller—who have netted a combined 40 goals in the Bundesliga this season, per WhoScored.com.

Juve head coach Massimiliano Allegri will hope to have Chiellini, 31, back from injury for the Allianz Arena clash, which is a possibility, per Corriere dello Sport (via Football Italia).

Chiellini has established himself as one of the best centre-backs in the world and makes up a formidable defensive trio when alongside Leonardo Bonucci and Andrea Barzagli, per football writer Sergi Dominguez:

Juve have not conceded in Serie A for the last nine matches and their defensive solidity could be the key against Bayern.

Chiellini is better qualified than most to give advice on how to stop Ronaldo and Messi, arguably the two best players in the world.

His tips on Ronaldo could give future Real opponents some hope of keeping the Portuguese quiet, but the fact that even Chiellini does not know how to stop Messi is an indication of just how good the Barcelona star is.