Jaissle’s side were well beaten 3-1 by fellow Premier League side Everton in a pre-season friendly on Wednesday (August 12).
Goals from Thierno Barry, a penalty from Iliman Ndiaye, and a wonder strike from Tyrique George secured the win for the Merseyside club.
Harvey Barnes pulled one back for Newcastle in the 85th minute, but it was too little too late for Jaissle’s young Magpies.
Newcastle have had a tricky summer transfer window, losing key player and missing out on priority targets.
When asked if a right-back and a central midfielder were needed, Jaissle said: "That's right. But you're smart. I will never tell you publicly.
“Like I said that already, we handle these things internally with all the respect to the decision makers. And will always continue like that."