Abdul Baba Rahman
Rahman [R] appears on the verge of moving to Stamford BridgeGetty

Augsburg coach Markus Weinzierl is demanding answers about the future of Abdul Baba Rahman, who is understood to be on the verge of joining Premier League champions Chelsea.

The Metro has reported that the Ghana international is due to have a medical with the Blues ahead of becoming the club's fifth signing of the summer, a move which follows Filipe Luis' return to Atletico Madrid.

But after being without Rahman, valued at €20m (£14m, $22m) according to club chairman Jonas Hoffman for the 5-0 friendly win over Toulouse, Weinzierl has become tired of the constant speculation regarding Chelsea and says he wants clarification over his future.

"It's clear that I and all of us here want the facts soon," he told German publication Kicker, according to The Evening Standard.

The sale of Luis back to Atletico leaves Chelsea light in defence as they attempt to retain their league title this term.

Branislav Ivanovic, John Terry, Gary Cahill and Cesar Azpilicueta made up – for the majority of the season – the best defence in the top flight last season but further options are few and far between.

Speaking before the Community Shield defeat to Arsenal, manager Jose Mourinho said he was in desperate need of additional defenders if Chelsea are to make a decent fist of clinging on to their title.

"We cannot go to the Premier League with five defenders – that's our weakness," Mourinho said, according to The Guardian.

"At this moment we have five: four to play and one on the bench. In this moment it's not a priority but in three days, if we lose one, it becomes a priority. Five is not enough. That's obvious.

"We have this time to organise that area where the quality is good but the numbers are not enough. I have people in mind but I know that the market sometimes has no rules.

"We, as Chelsea, we make our own rules. To make our own rules is to evaluate the players and to know the player's value, and to know when we have to stop and turn to another side, and think of another option."