As a result of his sending-off for fouling Mario Rui and then butting heads with the defender, Chile global Vidal will miss the second leg against Napoli at the Camp Nou, as will fellow Barca midfielder Sergio Busquets, who was also booked.
"They could've been there all night and not scored, but we conceded after one single error".
"After the equaliser, they opened up a little and we were able to hurt them more".
"If Barca didn't do today what they did three days ago (against Eibar) it's to Napoli's credit", said Gattuso. - Vidal is the first Barcelona player to be sent off in the Champions League in the knockout stages since April 2011, when Jose Manuel Pinto was dismissed against Real Madrid.
While he is keen to protect his legacy, he would like to see his old team bring in one of the world greats, even if he thinks he can not be surpassed. It is true that we have not generated much, but we knew that it was a matter of patience.
"We suffered tonight, tactically we were nearly flawless, but we could have done better and been more clinical".
Their pressing paid off on the half-hour mark, with Piotr Zielinski breaking free down the right before finding Mertens, who curled a magnificent finish past Marc-Andre ter Stegen. "A 1-1 draw is fine for the second leg".
"In the first half, we did not have any chances or shots on goal".
The Barcelona coach added: "We will have more options in the second leg, as it is unlikely a team will be able to defend for that long at Camp Nou".
Arturo Vidal saw red late on for two yellow cards and will miss the second leg, while Gerard Pique went off with an injury concern and could be a doubt.
"We will look for solutions", he told a media conference.