Dublin believe Donegal forward Paddy McBrearty suffered bruising and not a laceration or graze to his shoulder in last Sunday's league match in Ballybofey.
Dublin chairman Andy Kettle confirmed that a member of the Dubs' medical team visited the Donegal dressing-room by invitation after the game and examined McBrearty.
"Our medic, who knows one of the Donegal medical staff, did visit the dressing-room. My understanding is that he saw a bruise, not a laceration," said Kettle.
McBrearty was examined at Letterkenny General Hospital on Sunday night and had a series of injections. Donegal are understood to have taken photographic evidence of his shoulder after the game.
Kettle said he is "surprised and disappointed" that Donegal did not make direct contact with his county board over the allegations made to referee Padraig Hughes.
He claimed there was a "protocol in the GAA for things to be handled" and that this wasn't observed. He also said there was an onus on anyone making such allegations to prove them.
Kettle said there were no grounds for Dublin to launch their own investigation because there had been no contact from Donegal or Croke Park on the matter.
"I don't accept that something did happen. Until I am asked officially to investigate by the Donegal County Board I won't be doing anything," he said.
The allegation was made to referee Hughes at half-time and again to Michael Duffy, his replacement after Hughes damaged ankle ligaments, after the game
Kettle said he wasn't aware of any allegations until members of the media began contacting him on Monday evening.
"I am surprised that Donegal County Board have not officially contacted Dublin County Board. As far as we are concerned, officially, there is nothing to be investigated at the moment," he said.
"There is protocol in the GAA for things to be handled. I don't think that protocol was followed on this occasion."
Kettle doesn't believe Dublin have to make the running on an investigation, unless they hear official word from the Central Competition Controls Committee.
"First of all, was there an incident? That has to be established," he said. "It was a hard pitch. Some of our guys had bruises on their bodies as well. But I wouldn't say any of those was as a result of anything happening between them and Donegal players."
Kettle said he had spoken to referee Hughes at half-time to query whether Paul Flynn had picked up a yellow card, and "there was no mention of anything else."