They share a car to training every day, they room together for away fixtures.
Yet Matt Tubbs and Jayden Stockley also find themselves locking horns for Pompey’s sole striking spot.
The duo possess a close friendship which can be traced back to when both served Bournemouth.
Stockley remains contracted at Dean Court, but a six-month loan deal saw him reunited with Tubbs for a stint with Paul Cook’s side.
The opening three matches of this campaign have seen them alternate in the lone striker position in the 4-2-3-1.
Stockley was man of the match in the Capital One Cup victory over Derby, while on Saturday Tubbs opened his goal account for the season in the 2-1 win at Plymouth Argyle.
I am not one of those players who wishes someone is going to miss chances so I can get my chance, I want this club to move forward, I want this club to be out of League Two come the end of the seasonMatt Tubbs
Tonight the Blues head to Crawley, a former club of Tubbs.
And the 31-year-old is once again looking over his shoulder to see if his friend is ready to nudge him out of the starting line-up.
He said: ‘I’m really good mates with Jayden, I know him from my time with Bournemouth and have known him for years. We get on really well.
‘Jayden is from Bournemouth and I am from Mudeford so we meet halfway and then share the journey into training together.
‘We room together. We roomed together at Bournemouth and now we are rooming here.
‘Whoever the manager decides to pick – whether it is me or him – if it is him I will wish him all the best.
‘I am not one of those players who wishes someone is going to miss chances so I can get my chance. I want this club to move forward, I want this club to be out of League Two come the end of the season and the squad the manager has put together there is no reason why we shouldn’t.
‘We are different players. He is a big, robust target man but good with his feet and I am small and feed off scraps.
‘I think we are similar in our approach to hard work, though.
‘One of the mentalities at Bournemouth was there is no excuse not to work hard, even if you are having a bad game, your touch isn’t right and have missed a couple of chances.
‘You can see when you close someone down it gives the fans a lift and the players a lift as well.
‘I am sure there will be games coming up where we can play in the same team together. Regardless, as long as we both know as a team we have all got to stick together.’
Stockley’s only start for the Blues to date was in the 2-1 victory over the Rams.
Tubbs watched from the stands as the 21-year-old was named the sponsors’ man of the match – and agreed.
He added: ‘I think Jayden did fantastic against Derby.
‘I was sat next to Christian Burgess and said to him “Jayden is going to get man of the match now” – and was right.
‘He set up the goal and was the spark which set things off, closing people down and winning headers. He was fantastic.
‘It is only a matter of time before he gets his chance, while I have not actually done 90 minutes yet this season after a little knock on my ankle in pre-season.’