Today's revelation follows a similar bust-up last weekend when Viduka was left out of the squad to face Arsenal after he turned up late for the match having been late for training earlier in the week.
Viduka and Reid were reported to have patched up their differences this week but the relationship between manager and player now seems irretrievably damaged.
The rest of the squad were visiting HMS Ark Royal this afternoon on an official trip.
Meanwhile, David Batty is also out of the squad after failing to recover from a rib injury.
Portsmouth (from): : Hislop, De Zeeuw, Zivkovic, Stefanovic, Foxe, Stone, Quashie, Sherwood, Berger, Sheringham, Yakubu, Roberts, Taylor, Schemmel, O'Neil, Primus, Wapenaar.
Leeds (from): Robinson, Kelly, Camara, Matteo, Roque Junior, Duberry, Harte, Olembe, Pennant, Seth Johnson, Morris, Milner, Lennon, Sakho, Smith, Bridges,
Carson.