Todd said: "Russell has had to be second choice for much of his career, but all goalkeepers start out that way. You always need good goalkeepers. If you look at any club, you always have two good goalkeepers pushing each other. You have to have competition.
"He is a keeper of good potential. He is a tall, 6ft 3in, commanding goalkeeper who is still young and he will make good progress here.
"If Russell plays well in pre-season, there's no reason why he shouldn't push for a first-team place and become a very good goalkeeper for us."