Jackson is part of Team GB's four-man bobsleigh team, who currently lie in sixth position following three runs.
"It's worse watching John than being at the top myself as I have no control over what he does," Walker told BBC Sport.
"I haven't done enough practice watching him not to be nervous. He had a really good clear drive I think if he can repeat that he can jump into that third position.
"I asked if he was tired this morning and he said 'I'm ready'. He has a great future and with equipment and crew he could have a few good World Cup seasons in him - so you never know"
Russia currently lead the four-man event, with Latvia and the United States in second and third respectively.