The former Spurs chairman believes the Dane was below par during the 2-1 defeat at Crystal Palace.
Tottenham took the lead against Alan Pardew's side, with who else but Harry Kane putting Mauricio Pochettino's men 1-0 up.
And Sugar felt Eriksen, normally an astute performer, was particularly ineffective during the defeat at Palace.
Many supporters seemed to agree with the former Tottenham chairman, as Eriksen's usual high standards were nowhere near met in south London.
Was on the cards 2-1 .eriksen losing the ball too often today . Pardew the hero— Lord Sugar (@Lord_Sugar) January 10, 2015
Had to be new manager always makes the players step. Eriksen didn't have a good day today— Lord Sugar (@Lord_Sugar) January 10, 2015
As a Spurs fan you are immune to disappointment , same old, same old, one step forward 2 steps back— Lord Sugar (@Lord_Sugar) January 10, 2015
Tottenham's defeat brings them back down to Earth after a stunning 5-3 victory over table-toppers Chelsea in their last Premier League clash.
Now, Spurs must put the Crystal Palace loss to the back of their mind ahead of an FA Cup replay with Burnley, before Tottenham then host Sunderland in the league.