Rafael Benítez hopes to select Petr Cech and Demba Ba in his starting lineup for Saturday's visit of Wigan but the Chelsea interim manager will be denied his captain, John Terry, as the team seek to arrest the recent stuttering form that is jeopardising a place in the top four.

Terry reported discomfort in his right knee after training on Thursday, with the club's medical department having since confirmed there is inflammation on the joint. Benítez described the problem as "not serious" but the defender will sit out the game against the Latics, and potentially Thursday's Europa League trip to Sparta Prague, as a precaution, with both management and player wary that a relapse could hamper the 32-year-old's future participation this season.

The centre-half had initially damaged knee ligaments during the draw with Liverpool in November and had suffered swelling on the joint during his rehabilitation from that injury which effectively delayed his return. His start at St James' Park last Saturday was his first in the Premier League since the game against the Merseysiders, and only his second since the first week in October, and he will undergo intensive treatment over the weekend with an assessment to be made on his availability for the European fixture, and the FA Cup fourth-round replay with Brentford beyond, early next week.

Although Benítez has been cautious with the defender's participation, he is keener to involve Cech and Ba as Chelsea attempt to rectify recent slapdash form which has seen only three wins from 10 matches in all competitions. Both players were injured in last weekend's damaging defeat at Newcastle, missing midweek international friendlies for the Czech Republic and Senegal as a result, with the goalkeeper, who has managed to play only a limited role in training this week, having suffered a hairline fracture of a little finger that initially required a splint.

Ba, who is ineligible for the Europa League, had his nose broken in a clash with Fabricio Coloccini and travelled to Ortholabsport in Milan on Wednesday to have a facemask sculpted for him to wear. The carbon fibre mask has been personalised with his name and No29, with Benítez putting the forward through set-piece routines against Chelsea's centre-halves on Friday to ensure he is ready for the physical challenge to come against Wigan.

"It is not a question of 'risk' – because of the mask, that will be fine," said the manager. "The question is whether he has enough confidence to play 100% or not. Talking with him, he says he's fine. I was practising today with free-kicks and corners, balls in the air. It's not the same – a centre-back of your own team is more careful than one of the opposition – but we were trying to check and see if he could cope. Maybe [he will take a whack], so we may have to be careful, but we will see. He feels confident."

Benítez's position will come under greater scrutiny if Wigan, entrenched in another relegation battle, are not beaten as Chelsea's recent run threatens their qualification for the Champions League. The team have won only one of their past four home games, albeit that victory was against Arsenal and was attended by Roman Abramovich.

The interim manager has not spoken to the owner since that fixture but, in conversations with the sporting director, Michael Emenalo, believes his position is not under immediate threat. "I have a contract until the end of the season and people can be talking and talking [about the manager's position]," he said, "but all I can do is try and win games. [The owner] wants to be in the top four, obviously."