Martin O’Neill insists his search for reinforcements to make his Aston Villa side a force to be reckoned with will go on until the August 31 transfer window slams shut despite the capture of his sixth summer signing.

Rangers’ defender Carlos Cuéllar was having a medical at Villa’s Bodymoor Heath training ground today after a deal was agreed between Villa and the Scottish Premier League giants.

Cuellar triggered a release clause in his contract with Rangers and leaves them in a £7.8 million transfer just days after they bombed out of the Uefa Cup - a competition he hopes to now pursue with his new Villa team-mates.

If the 26-year-old Spaniard’s medical goes through today he will join midfielder Steve Sidwell, goalkeepers Brad Friedel and Brad Guzan, and defenders Nicky Shorey and Luke Young in the new-look Villa squad.

O’Neill however is still chasing new arrivals with the transfer rumour-mill in overdrive linking Villa with possible interest in Chelsea and England midfielders Joe Cole, who is rated at £15 million, and £11 million rated Shaun Wright-Phillips.

The Villa boss, never one to divulge his targets, said: "If we’re going to try and compete, even at Premier League level let alone Europe, we need a decent squad. So we need to keep adding quality if we can.

"We’ve lost Freddie Bouma and we were quite thin on the ground before that. That sort of injury can happen at any given minute. Therefore we need to try and safeguard as much as we can.

"What we’ve done is bring in a recognised right-back and a recognised left-back to help us. We didn’t have the right-back last year but it wasn’t for lack of trying.

"We’ve not finished. We’ll still have some players coming in to give us a chance and if we’re lucky enough to qualify for the group stages of the UEFA Cup that would take us right up to Christmas and we’ll most definitely need the squad.

"Last season we were exceptionally lucky with injuries. Eight or nine players played over 30 games and we didn’t have big runs in the FA or League Cup - therefore we were able to concentrate on the League.

"All that could change this season and the fact is that we need the squad to be bigger to cope with that. That’s what we’re trying to do."

Bouma suffered a badly dislocated ankle in a horror injury at Villa Park against Odense in the Intertoto Cup and faces five months on the sidelines after emergency surgery to put a plate in his ankle.