The Uruguayan was fearful that the Scotland international had sustained a broken metatarsal in his side's 2-0 defeat to Arsenal last week, but was relieved to find that the injury was not serious.
Poyet told reporters: "Fletch is back and he's been training this week similar to before the Stoke game so I am really looking forward to seeing him on the pitch on Monday.
"I feared he had broken his metatarsal. That was a shout. The doctor said to me it could be that because of the pain he had and where it was.
"Lucky enough it was not, which is great. He has had two or three days rest with the bruising."
Sunderland are 18th in the Premier League ahead of their match with Palace.