Walker arrived in the summer as backup to No1 Jussi Jaaskelainen and Allardyce is delighted with his current goalkeeping stocks.
"Jussi slipped up on the first goal on Saturday but that is the only time he has slipped up this season," Allardyce said.
"He has been very good when we have needed him to be good.
"He has also been lucky as well because he has been unemployed a lot of the time this season because the players in front of him have been so good.
"We have to give Ian Walker as much practice in the first team as we can to make sure he is prepared for when we have to call upon him.
"We are faced with playing 55 games and Jussi is not going to play 55 games because of injury, suspension and squad rotation.
"No disrespect to Kevin Poole but if we needed to use him for more than one or two games he wouldn't have been fit to keep goal for too long.
"We have been dicing with death and we needed a goalkeeper with the quality of Ian Walker."