Holloway had hinted that the deals had been completed after the Eagles' 3-1 win over Sunderland on Saturday evening.
"The chairman and I have been working so hard to bring some more people in," Holloway told Sky Sports after the game.
"I think we've got two done today, hopefully we'll get another three or four done."
He added: "We need to get some strength in depth to help these boys and I won't block up the youth either because to see Jonny Williams and Stewie O'Keefe coming on, that's the Palace way really."
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