The creative midfielder was frustrated with the Donetsk outfit's loss at Stamford Bridge, but remains hopeful they can reach the next round
The Ukrainian champions appeared to be on their way to a 2-2 draw until Victor Moses helped the hosts to the full three points with a stoppage-time goal, much to the frustration of the Brazilian.
"We are very sad. We know that our performance was quite good and we didn't deserve this defeat, especially the way it was, conceding a goal in the last minute," the Brazilian told reporters.
"So we are really sad, but hopefully in the next match we will win again."
The attacking midfielder then went on to discuss his side's chances of making it to the knock-out stages, and stressed that Juventus could cause them problems in their last group match.
"Juventus have a great squad, full of good players. They are still in the game because they will host Chelsea in next round and certainly they will do their best to win.
"But it's all in our hands. We must win away [against Norsjaelland]. We know it's hard, but our qualification will be decided at home against Juventus if we do it."
Shakhtar take on Nordsjaelland on November 20, before hosting Juventus on December 5.