Alberto Cavasin suffered more injury woe as vice-captain Liam Kelly came off within the first five minutes in their 1-0 loss against Portsmouth.

Christian Burgess scored the only goal of the game as he headed in at the back post from a corner in the second half.

There was a penalty appeal for Orient in the first half after Yvan Erichot was bundled in the box but it was waved away and the Italian also substituted Paul McCallum for Alan Dunne before the second half.

Cavasin said: “There is a sadness of losing a good match as I thought we played well in the first half, but we have to recognise the fact we lost against a good team so I can say nothing more about that. 

“Penalty decisions is something I have never commented on in my career, you get what the referee gives you, and I do not want to talk about.

“Not having Kelly anymore we had to decide who to put in the midfield as we did not have the same kind of player, with the same characteristics as Kelly had, so we had to change module.

“And in the last 20 minutes of the second half we were not as compact as we wanted to be so on that occasion we had to make substitutes to try and equalise.”

It is a worrying look at Orient’s midfield at present as Kelly now joins the likes of Nigel Atangana and Harry Cornick on the side lines.

Robbie Weir is still suspended following his sending off against Plymouth Argyle and will miss the next home game against Luton Town.

Once again it was set pieces that allowed Pompey to gain the three points, something Cavasin is hoping to work on next week in training.

“We do not know the extent of Kelly’s injury, but we do know it is a muscular type problem so we are still waiting on the exams and as soon as we know we will see what we can do about it,” added the 60-year-old.

“Set pieces is something I did not get the chance to work on in these five days of being in charge so it is something I will definitely look to improve."