Parker has been an inspirational figure for a West Ham side whose relegation battle continues against Manchester United on Saturday.
He has played through injury and took the field only hours after the death of his father, Mick.
Committed: Parker (right) has given all to the West Ham cause this season
Hammers boss Grant said: 'Without any doubt, he's the player of the year. I don't see anyone better. He's a player who gives everything. He could fit in any side.'
The result of the PFA Players' Player of the Year will be announced this month.
Stay up and the future's bright: Grant rallies Hammers for relegation dogfightWest Ham have suffered most from referees decisions, claims GrantWest Ham boss Avram Grant handed break in relegation dogfightAll the latest West Ham United FC news, features and opinion