Eddie Howe says Newcastle have "massively over-achieved" this season and will have to cope with soaring expectations among the success-starved fanbase.
The Magpies secured a return to the Champions League after a 20-year absence when Monday's 0-0 draw with Leicester guaranteed a top-four finish in the Premier League.
That represents a significant upgrade on the more modest ambitions Newcastle had at the start of the campaign.
"The dynamic will have changed for us," Howe told reporters on Friday.
"I think we have massively over-achieved this year for where we were at the start of the season and to keep over-achieving -- and that's what we're going to have to do to match the expectation -- is going to be our biggest challenge."
Newcastle have already spent more than £250 million ($309 million) since the club's Saudi-backed owners took charge in October 2021.
Now they have qualified for the Champions League, Newcastle will be attractive to a better calibre of player than Howe might have anticipated when he started planning for next season.
Newcastle, without a major trophy since 1969, have been linked with West Ham midfielder Declan Rice and Leicester playmaker James Maddison.
Asked if his wish-list would include "marquee" signings, Howe said: "Yes, there would be players we'd love to bring in that would be classified in that bracket, I'm sure.
"For me, it's more about the role they can fulfil in the team -- whether that's viewed positively or as a marquee signing, then great.
"I'm not in my mind thinking, 'We have to have one of those players that ticks that box for the supporters'. As much as I'd love to do that, it's about finding the right player in the right position who I think makes us better."
Speaking ahead of his team's final game of the season against Chelsea on Sunday, Howe warned that Newcastle would have to continue to invest shrewdly, despite their new-found wealth.
"I still don't know what my budget is at this moment in time, but there will have to be some expenditure," he said.
"It will have to be controlled. It will have to be under FFP (financial fair play) restrictions, which we have worked under and will continue to work under. They are definitely impacting us and what we will be able to do."
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