Barry Bannan and Jonny Williams are pushing hard for starting spots in Crystal Palace's midfield, according to boss Neil Warnock.
Bannan and Williams impressed in Palace's 3-2 extra-time Capital One Cup home defeat to Newcastle on Wednesday.
New Eagles manager Warnock fielded a completely-changed XI in a bid to assess the depths of his Selhurst Park squad.
The former Sheffield United boss was pleased with his side's battling qualities despite Paul Dummett heading the extra-time winner for Newcastle.
And Warnock tipped Bannan and Williams to push the likes of Mile Jedinak and Joe Ledley for starts in Palace's midfield.
"I thought the players were fantastic and played without any fear," said Warnock.
"I'm really proud of them.
"We just couldn't have played anyone who had featured at Everton because of the amount of work we did up there.
"So considering we made 11 changes we performed very well.
"I know people expected that would weaken us but the way the lads performed, I honestly don't think it did.
"So we've got a lot of players going well and now I've got problems with who I can leave out to be honest.
"Guys like Barry Bannan and Jonny Williams went well so that will make selection tough, and that's a great problem to have."
Emmanuel Riviere ended his six-game goal drought with a smartly-taken brace that nearly sent Newcastle through in normal time.
The £6million summer recruit got off the mark at his new club in style, despite missing several early half-chances.
Dwight Gayle's penalty initially handed Palace the lead, and teenage debutant Sullay Kaikai plundered an equaliser in second-half stoppage time.
Full-back Dummett then headed home in extra time to earn Newcastle a trip to Premier League champions Manchester City in the next round.
Newcastle manager Alan Pardew believes Riviere can now go from strength to strength after ending his dry spell in front of goal.
"Anyone who has seen us play this year will know the top of the pitch has been an issue for us," said Pardew.
"We've just not had that cutting edge.
"So perhaps the two goals from Cisse against Hull on Saturday and two from Manu against Palace is a big lift for the club.
"I'm so pleased for Manu, he's worked tirelessly this season, and he deserves those goals.
"That will give him a real lift."