Steve Bennett had been booked to referee the game at St Andrew's but he has been appointed referee for the UEFA Cup 1/4 Final, 2nd leg game between Parma and Austria Vienna in Italy on Thursday, April 14th.
Peter Walton has taken charge of just the one Blues fixture so far this season whilst the Northamptonshire-based official has taken charge of two Pompey fixture's.
The Blues game Peter Walton refereed earlier this season was the 2-1 home win against Southampton on 22nd February when Blues had no players booked but David Prutton and Olivier Bernard were booked for Saints.
The last time that Peter Walton refereed a Pompey game was in their 2-1 away defeat to Everton on 4th January. No players from either side were booked during the game at Goodison Park on that day.
Mr Walton had also taken charge of Portsmouth's home win against West Brom back on 4th December when once again no Pompey players were booked although two Baggies players received yellow cards.
In total Peter Walton has taken charge of 14 Premier League games so far this season in which he has handed out 37 yellow cards and just the 1 red.
Mr R Burton and Mr T Massey will be Peter Walton's assistants for the game at St Andrew's on Saturday evening.