Oscar battles with Glenn Whelan during the first half of Chelsea's win over Stoke. Getty Images

José Mourinho has conceded that Chelsea midfielder Oscar was just not good enough against Stoke, but shielded fellow midfielders Cesc Fàbregas and Nemanja Matić from similar criticism following the 2-1 win at Stamford Bridge.

Oscar returned to the lineup for the visit of Mark Hughes' side after starting Chelsea's last Premier League match at Hull on the bench, yet made little impact and lasted just 45 minutes before being replaced by Diego Costa at half-time.

Such a lacklustre display was symptomatic of his 2014/15 campaign so far. While the Brazilian playmaker clearly possesses great ability, his lack of consistency can often prove frustrating and recent reports have suggested that he, along with compatriot Ramires, could potentially be offered to Juventus as part of a future package deal for Paul Pogba.

Typically defensive of his own players no matter what their faults, Mourinho stopped well short of belittling or vilifying Oscar but did acknowledge that he was some way short of his best.

"No, I don't think he had a bad performance, I just think he was not good enough, which is a huge difference," he was quoted as saying by the Daily Mail.

Performance slowdown

Fellow midfielders Fàbregas and Matić, meanwhile, have provided the bedrock for much of the success achieved by Chelsea in recent months, yet both have shown signs of regression of late and their partnership is arguably not as strong as it once was.

Fàbregas' productivity, in particular, has slowed somewhat during this calendar year. Although he still sits comfortably atop of the Premier League's assists chart with 16, he has only registered three in 2015 and Chelsea are likely to need him to return to his best with Costa facing at least two weeks on the sidelines after suffering yet another recurrence of a long-term hamstring problem.

"For me football is not just mathematics. When some people write that Fàbregas drops his level because the number of assists are not the same, the number of assists are probably not the same because the player that he assists does not score," Mourinho added.

"Matić, he was suspended, and after the suspension he was injured celebrating in the final, so he went back and he was not in the best condition. I always think stability is very important in a team, and it's not in April that you are going to make important changes."

With Costa likely to miss important fixtures against struggling QPR and top-four rivals Manchester United in April, Mourinho will no doubt be looking to Eden Hazard and Loïc Rémy to provide the goals that will help to ensure his team do not relinquish control in the race for the title.

Hazard was favourably compared to Lionel Messi and Cristiano Ronaldo following his excellent performance against Stoke, while Frenchman Remy has scored winning goals in each of Chelsea's last two top-flight fixtures.