Gianluigi Buffon may regret his criticism of referee Michael Oliver after being sent off against Real Madrid on Wednesday, according to Juventus icon Alessandro Del Piero.

Goalkeeper Buffon was shown a red card for his furious reaction towards the English official, who awarded Madrid a crucial stoppage-time penalty in the Champions League quarter-final second leg at the Santiago Bernabeu.

Juve cancelled out a 3-0 deficit to draw level in the tie, only for Cristiano Ronaldo's penalty to send the defending champions through to the last four following Medhi Benatia's clumsy challenge on Lucas Vazquez.

Buffon claimed after the game Oliver had a "trash can" instead of a heart, while he also referenced the first leg in Turin when Juve had Paulo Dybala sent off.

However, while understanding the obvious frustration after going out in such dramatic circumstances, Del Piero disagreed with his former team-mate's post-match analysis.

"When Gigi spoke about the referee I couldn't understand him, honestly," the former Italy international said on Sky Sport Italia.

"I don't understand why he talked about the previous fixture. In football you analyse the present.

"I understand it's a frustrating situation but I think he will think about what he said and possibly say different words in a few days."

With Buffon sent off, Ronaldo scored past substitute goalkeeper Wojciech Szczesny as Madrid triumphed 4-3 on aggregate.