Paul Cook is remaining calm despite Gary Roberts limping away from Bognor last night with his left knee in a brace.
The 31-year-old picked up an injury just before half-time following a tussle for the ball with Doug Tuck.
I would imagine he will now go for a scan and that will reveal the full extent, we just wait and seePaul Cook
Physio Sean Duggan worked on the midfielder on an outside treatment table at the interval, yet he had to be substituted.
The Blues will today learn more about the injury, with a scan also planned.
The possibility of losing Roberts is a big fear to the Fratton faithful, who have recognised him as a key man in the campaign ahead.
But Cook, whose side drew 1-1 with the Rocks, was refusing to get carried away by the potential for bad news.
He said: ‘I thought the referee should have given a foul but you get these injuries.
‘It’s disappointing with Gary but that’s football.
‘We have seen it before. We all want to stand our ground and have everything going our way but these injuries are always sent to test us.
‘Somebody coming out of the team always gives someone else an opportunity.
‘It looked like Gary just fell over, yet the ground was very dry all night and when it is like that the studs can get stuck in, that is the way it is.
‘It is far too soon to say what is wrong. We will come in this morning, assess how it settled down overnight and take it from there.
‘I would imagine he will now go for a scan and that will reveal the full extent. We just wait and see. He is a bit disappointed. Gary is a good lad, a good pro and wants to do well for the club.’
Matt Tubbs gave the visitors an early lead during a dominant first-half in which they dictated the match.
Adam McGurk came on for Roberts after the break and Jamie Howell’s side levelled through a well-taken goal from former Pompey Academy striker Alfie Rutherford.
Disappointingly, the Blues had no response and added another draw to the 1-1 result at the Hawks last weekend.
They will now face Gosport Borough at Privett Park today (3pm) as they bid to pick up a first win under the new boss.
Cook added: ‘I thought we lacked penetration at times.
‘I thought we gave the ball away too cheaply at times but hopefully we learn bits from the game.
‘I’m disappointed we conceded a poor goal and disappointed we didn’t have too many clear-cut chances.
‘We huffed and puffed without ever looking like scoring.
‘We have to put those teams to the sword and move the ball quicker in the final third.
‘But Rome wasn’t built in a day, we are a work in progress.
‘I am disappointed we didn’t win but how pre-season is, if you win last night and win at Gosport, great – then you could lose to Dagenham.
‘I think the main thing is we keep working towards the Dagenham game.
‘That is by far and away our most important match.’