Celtic will take on Hearts away from home in the Scottish Premiership on Sunday afternoon.
Brendan Rodgers’s side will head into the game at the Tynecastle Stadium in Edinburgh as favourites.
Former Celtic striker Walker has backed the Glasgow giants to pick up all three points from the encounter.
Ryan McGowan in action with Celtic's Eoghan O'Connell
Walker has also stated that Celtic central defender Eoghan O’Connell will be the key player in the game.
“[It is] amazing he hasn't played more often in recent seasons given Celtic's problems in defence,” Walker told Sky Sports about O’Connell.
Celtic manager Brendan Rodgers
O’Connell is a 20-year-old promising young centre-back who has been quite impressive in pre-season.
The youngster has made just a handful of appearances in the Scottish Premiership for the Glasgow giants so far in his career.
Celtic are favourites to win the Scottish Premiership title this season. Old Firm rivals Rangers are expected to challenge Rodgers’ side for the title, but the Hoops will feel confident about their chances.
Aberdeen and Hearts are also expected to challenge for the Scottish Premiership title this season.
Eoghan O'Connell celebrates with Celtic teammates