Defeat to their Group E rivals would make qualification for the knockout stages of the tournament very difficult, with Serie A champions Juventus providing tough opposition.
The Londoners have arguably the toughest run-in of any team in their group and Mata is aware that three points will be valuable in their quest to defend their European crown:
“It’s time to move on and to focus on the Champions League match this Wednesday.” He said.
“It’s like a final for us if we want to finish first in our group.
The Blues lost their last encounter with the Ukrainian outfit, but Mata believes that they can improve this time out:
“In Ukraine, Shakhtar proved to be a top team who are able to beat anyone.
“Even so, we always have a great support at the Bridge and I’m confident that we will get a victory to face the last two games in a good position.
“Champions League nights at the Bridge are always special.”
But he is confident of returning ahead of Wednesday:
“After such a huge effort during 120 minutes I was forced to rest a few days with a hamstring injury.
“That’s why I missed our game in Wales against Swansea.”