Chelsea star Pedro Rodriguez suffered a disappointing injury in his side's 1-0 win in their Europa League fixture.
Brazil star Willian scored the only goal that handed the Premier League side the victory on Thursday, September 20.
The former Barcelona star was helped out of the pitch after colliding with goalkeeper Alexandros Paschalakis towards the end of the game.
He was helped out of the pitch by Chelsea medical staff which saw his side down to 10 men in the final few seconds after they had made all their subs.
Maurizio Sarri is uncertain over the full extent of the damage, and if Pedro would be fit for the Premier League clash at West Ham on Sunday, Sarri is hopeful that the 31-year-old would return to action soon enough.
"I don't know. The problem is shoulder, but I don't know exactly the situation ,' Sarri said.
"I have spoken with the doctor, but only for a few seconds. The doctor told me that probably it's not a very serious injury. "
Chelsea rank second on Group L table behind BATE Borisov who defeated Vidi FC 2-0 away from home in their other group encounter.
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