And Paul Cook has pledged the youngster will continue to be eased back into first-team action following a long-term knee injury.
Whatmough is currently on a month’s loan at the Hawks in a bid to earn match-day action.
The teenager made his bow in last weekend’s 2-0 loss at Hemel Hempstead, coming off the bench in a 15-minute cameo.
On that occasion, Hawks boss Lee Bradbury opted to employ Whatmough sitting in front of the back four.
It was his first appearances since sustaining cruciate knee ligament damage against Cheltenham in March.
The Westleigh Park outfit have another three matches scheduled during his spell.
And Cook insists an agreement is in place with Bradbury to ensure the Gosport youngster will be gently introduced to more football during that period.
He said: ‘It is massively important for Jack to be at the Hawks and great thanks to Lee (Bradbury).
‘Jack is going to need managing for a few games, there are a certain amount of minutes which he must play, so the first month will be littered with being a sub, coming on and coming off.
‘Fans should not read anything into that.
‘It’s just getting Jack’s confidence back playing football and hopefully we can see him get back into our first-team sooner rather than later.
‘In terms of how long he will stay, we’ll see how it goes, let’s just let him go and play footy.
‘They have a plan, the clubs have discussed at length a programme so everything is being minuted and itemised in terms of minutes on the pitch, then after that month hopefully Jack will be good to go in his football career.
‘Jack has trained so hard to get back – and it’s also nice for Havant, who might boost their gates a little bit.
‘I’m sure there will be Pompey fans going there knowing Jack is playing. Maybe we can all nip down and watch him play!’
Whatmough had made 36 appearances for the Blues before last season’s injury in freak circumstances.
Despite recovering narrowly ahead of schedule, the 19-year-old had not played any competitive football until arriving at Westleigh Park.
Now Pompey are hoping Whatmough, who is contracted until the summer of 2017, will be presented with more first-team action to maintain his rehabilitation.
However, Cook is not concerned what position Bradbury decides to employ the central defender.
Pompey’s boss added: ‘I have problems picking my own team, I am not picking Lee Bradbury’s team!
‘If he picks Jack as a holding midfielder he might see that position in him, I haven’t seen that in Jack yet.
‘But if Lee decides to play him there good luck and it will do Jack great experience to play in a different position.
‘It’s just about minutes on the pitch.’