When every England player is available it is most likely that Wayne Rooney will start up front with Michael "made-of-glass" Owen because of their reputations more than anything. In the likely event that Owen gets injured then Rooney's strike partner is up for debate.
Currently it seems that Fabio Capello likes Defoe and plans to use him as Owen's replacement if the Newcastle striker continues to have problems. However, the likes of Peter Crouch, Dean Ashton and Theo Walcott are all waiting in the wings to take his place and I believe that next season is an extremely important one for those forwards vying for that England place.
Defoe has an advantage over the rest of his competitors as he is virtually a guaranteed starter for his club whilst Crouch can't get a game at Liverpool (so he should move here), Walcott won't see much regular first-team action at Arsenal and Ashton still has to prove his fitness at West Ham after a season blighted by injury.
If Defoe can outscore Michael Owen or even better, become the top scoring Englishman in the Premier League then the England boss will have no choice but to play him. Unless he decides to go with Rooney up front on his own...
But what about Glen Johnson? He must have a shout at making himself a regular in the England starting line up. His competition comes from the likes of Gary Neville, Wes Brown and Micah Richards.
The injuries to Neville and Richards have helped Johnson's cause and it may be possible that Neville may never get back to his best after a whole season out. Richards still has much to learn and may be favoured at centre back which would just leave Wes Brown to oust.
That won't be easy but if Glen continues to develop the way he has this season then there is every chance that he will be England's first choice right back for the 2010 World Cup, especially as he offers a potent and quick attacking threat down the right which is something we would lack with Beckham or Bentley in the side.
Then we have David James who is currently established as England's number one. He faces direct competition from Scott Carson, Paul Robinson and Chris Kirkland but given the season the former two have had, they will need to improve tenfold to even threaten Jamo's position whilst the latter has had a career plagued by injury and I wouldn't bet against him suffering another one next season.
In my opinion, James has got to be wary of the young guns such as Joe Hart and Ben Foster. Hart has had an excellent season at Man City and will only get better whilst Foster also has Premier League experience and it will only be a matter of time before he is Manchester United's first choice 'keeper.
Even if Jamo keeps performing to his best, he may still be replaced by the youngsters as Fabio looks to the future. However, Harry Redknapp will tell you there is no substitute for experience and I think that the Pompey stopper could be saved for the big qualifiers against the likes of Croatia and the Ukraine.
Out of the three Pompey players currently representing the national side I think that Glen Johnson has the best chance of playing at the next World Cup. James' age may count against him whilst Defoe will have to do something special to get in the team ahead of Rooney, Owen and whoever else fancies their chances.
Still, there's every possibility that Peter Crouch or Shaun Wright-Phillips may be representing Portsmouth at the next World Cup (if we qualify!).