Neil Black, the UK Athletics performance director, has a couple of difficult decisions to make today as he finalises his squad for next month's World Championships in Moscow.

After last weekend's Sainsbury's British Championships, there are 18 athletes whose places for Russia are guaranteed ahead of the final selection to be announced today.

One dilemma facing selectors concerns the third spot for the men's 100 metres. Dwain Chambers took the title in Birmingham to secure his place, while James Dasaolu's semi-final run of 9.91 seconds, the second quickest time ever by a Briton, makes him a certainty.

The remaining place is between Harry Aikines-Aryeetey, who ran an 'A' qualifying standard and personal best 10.08sec in finishing second to Chambers at Birmingham's Alexander Stadium, and Adam Gemili.

The latter was not competing in Birmingham, as he was busy winning gold at the European Under-23 Championships in Finland, and he does not have the 'A' standard.

The result could mean Gemili, the world junior champion who reached the London 2012 semi-finals, is overlooked for the 100m and is picked instead for the 200m, for which he does have the qualifying time, and the sprint relay.

The other decision involves Olympic gold medallist Greg Rutherford. The long jumper only has the 'B' standard and did not compete in Birmingham as he is struggling with a hamstring injury. In his absence, Chris Tomlinson took the title, but missed the 'A' standard.

"There aren't too many headaches," said Black, who is also acting head coach after Peter Eriksson's departure. "As everyone knows, there are one or two circumstances where we say 'what are we going to do when there is more than one 'B' standard to consider?'

"Perhaps people have not achieved the standard they would like to in the time frame we have allowed. But the dilemma that might have been for the men's 100m is a different or lesser one in some ways as a result of the brilliant performances and the circumstances surrounding Joel Fearon."

Fearon, who had the 'A' standard coming into the weekend, must have thought his hopes of achieving an individual spot had gone following his disqualification for a false start in the semi-finals.

Black added: "None of them [the selection issues] is as significant as people perhaps perceive them to be, but that's because we clearly understand every aspect of the [selection] policy. What I have told people is that, for anybody who is being put forward as a possibility at that level, we have to have a detailed history leading to where they are and to a clear objective of where we believe they will be in the future.

"There are probably one or two that will be difficult, but in that circumstance I will decide."

Black is confident heptathlete Jessica Ennis-Hill will be available for Moscow after an ankle complaint.