SAM Allardyce has jumped to the defence of his Reebok back line - but warns there could be changes at Fratton Park on Tuesday night.

Many felt it was a case of the same old story when Wanderers conceded the added time Dwight Yorke goal in the Lancashire derby.

The Reebok boss stated "we can't defend" shortly after the game on Saturday, but after a couple of days of contemplation he has stood by his side in time for the game at Portsmouth.

"I have lost count of the number of people who have spoken to me and complained since Saturday about how it is the same old Bolton story," he said.

"But the facts don't back it up, because in the previous 12 games we had not let a late goal like that in.

"In seven of our last eight games last season we kept a clean sheet, so there is no defensive problem here.

"The point is we have to remember the lessons we learned last year and towards the end of a game we must get out of the box.

"We should not be on the back foot in our own area when they are playing balls from their own half. Someone needs to take charge and be brave enough to lead the line out.

"We put too much pressure on ourselves staying back."

Wanderers did keep seven clean sheets in the final 10 games of last season, and the last time they threw away points in the dying minutes was on February 22 - some 13 Premiership games ago - when Ole Gunnar Solskjaer scored a 90th minute equaliser for champions Manchester United.

But Allardyce is considering defensive changes for the Fratton Park clash because of the number of goals leaked in the opening two games of the season.

Simon Charlton is making good progress although he is still short of games, while the more experienced Anthony Barness could replace Nicky Hunt at right back.

Allardyce said: "I think I might make a few changes as I have given this group a chance and it has conceded six goals. That has to stop so I may consider a little shifting round.

"Nicky has done very well but I can't see himbeing myfirst

choice in that position. He showed great character in coming through a dodgy start against Blackburn, and his progress is like having a new player in the squad."

It is likely Kevin Nolan will continue in midfield with Per Frandsen again on the bench.

Allardyce said: "It's very disappointing for Per because of the player that he is, and the dedication and commitment he has shown.

"But he will play more games."