The Premier League leaders visit Pardew’s team hoping to equal a club-record run of 11 straight wins, when the in-form Costa is again expected to be key.
Since Antonio Conte’s summer appointment as Chelsea manager, Costa has excelled with his work-rate and in scoring 12 goals in 18 games, perhaps establishing himself as even more influential than Eden Hazard.
Delaney, meanwhile, has re-emerged as significant to Pardew’s team having lost his first-team place to the £10m James Tomkins earlier in the season.
Their only clean sheet in the league so far came when he was recalled against Southampton, after they conceded five at Swansea while he was a substitute, and with the Corkman outstanding in central defence.
The 35-year-old’s unlikely renaissance will therefore next be tested against one of the division’s most in-form players and most in-form team, one Pardew had earlier described as “unbeatable”.
“We’ve always had great admiration for (Costa),” said Pardew, 55.
“He’s competitive. We won there last year and Delaney had one of his best games for me against Costa that day, and he’s going to have to do a repeat performance because the guy is at the top of his game.
“We had Zlatan (Ibrahimovic) the other night, Costa this weekend, so my centre-halves will have had a real test. Most people would say Chelsea have all the qualities of a team that could win the Premier League. But I do look at a couple of the others and think their competition is as strong as it has ever been.
“United were very good the other night. We played to our maximum (on Wednesday) and still got beat. And Tottenham, Man City, Arsenal; it’s a tough league this year so Chelsea still have a lot to do.”
Meanwhile Antonio Conte has challenged his Chelsea squad to put “passion” before money as Oscar closes in on a £52m move to China.
Blues manager Conte insists he remains proud of Oscar’s attitude, despite l amenting the Brazil forward’s impending switch to Shanghai SIPG. Oscar’s January transfer for an expected £400,000-per-week wage should be confirmed shortly, with Conte branding China’s spending power a “danger” to global football.
The Stamford Bridge chief revealed Oscar will leave with his blessing, but also accepted football’s ever-increasing battle between ambition and money. “I think the most important thing for us must be the passion. Okay? The passion for football,” said Conte. “If you haven’t got that, it’s no good. No good. I repeat: this concept is very important. Before the money must be the passion, the passion for the sport, for football.
“We started to play when we were children without money, and only for the passion. Then, also, came money but the passion is more important than money, for me. Oscar is a really good player.
“For me, I was proud to have him in my squad and have him as my player. I’m proud of his attitude, his commitment and his behaviour, which have been fantastic.
“I have great respect for every decision made by a single player. If you ask me, ‘are you sorry?’, then yes, I am sorry. I am sorry because he’s leaving as a really good player and a really good man. I must be honest about this. But, also, I understand him and his decision.”
Eden Hazard should be fit for today’s clash at Selhurst Park as Chelsea bid to equal their club-record 11-straight Premier League wins. Conte has insisted Chelsea’s winning run only serves to increase the size of his side’s weekly challenge.
“It’s more difficult for us to continue this way than for our opponent,” he said.
“Because our opponents have nothing to lose.”