Anthony Stokes, Stefan Scepovic, Leigh Griffiths and Manchester City-owned John Guidetti are the four recognised forwards in the Hoops squad.
However, it is Aberdeen’s Adam Rooney who is the top scorer in the Premiership with 17 goals at the moment, with Dundee’s Greg Stewart second with 13 goals.
Former Celtic star Walker believes that manager Ronny Deila needs to address this issue in the summer.
“Maybe the one thing they require is an out-and-out number one striker,” Walker told Sky Sports. “It’s the one thing that’s missing from their assault on the Champions League qualifiers.
“I know Leigh Griffiths has been in recent goal-scoring form but it’s surprising at this stage in the season when you don’t see a Celtic player at the top of the scoring charts.”
Meanwhile, City-owned striker Guidettii will find out on Thursday if he will be punished for singing an allegedly 'offensive' song about the demise of Rangers, according to Sky Sports.
The 23-year-old Sweden international striker is in hot waters for repeating a chant sung about him by Celtic fans during an interview on Dutch TV show FC Rijnmond.