Cesc Fabregas says Chelsea will have to attack in the second leg of their Champions League clash with Barcelona because trying to play defensively at the Camp Nou is a "suicide mission."
Chelsea will need to score as Barcelona took an away-goals advantage with a 1-1 draw at Stamford Bridge on Tuesday night.
Willian had given Chelsea the lead before Lionel Messi equalised in the 75th minute with his first goal in his ninth appearance against the Blues, ending his longest goal drought against any opponent.
Barcelona controlled 73 percent of possession, though Chelsea outshot the visitors, and Fabregas warned that a superior effort will be needed in Catalonia to advance to the quarterfinals.
"It was such a shame really," he told BT Sport. "I thought we were very good and went with the game plan and we executed it really, really well. They had a few chances, they are one of the best teams in the world.
"But we were compact, we were solid, we played as a team, we created many chances. Willian could have easily scored a hat trick today.
"So overall a fantastic performance [but] in the end a shame. We go home thinking we completed a good work, we competed very well [and] we should be proud of that but at the same time we go home sad. It was an unfair result.
"[The game] it's still open, but we know we have to play a very excellent same again to compete.
"[To play] 90 minutes there defending -- can be a very long 90 minutes, it's basically a suicide mission. We have to feel that we can hurt them."
Chelsea goal scorer Willian was also disappointed with the end result after striking the woodwork twice.
"I'm happy with the goal but I'm a bit sad with the result," he said. "I felt we deserved to win today. Of course, they had more possession but we created a lot of dangerous chances to score.
"I think it's still open. We have to go there and play the same game, compact and fight with every ball and I think we can do that.
"I was a bit unlucky but we have to keep working and look forward to the other game."