Eddie Howe admits Newcastle's new-found status as a threat to the Premier League's big guns will make it harder to sign players from their rivals in future.
The League Cup finalists added Everton forward Anthony Gordon and West Ham full-back Harrison Ashby during the January transfer window.
But their long-standing interest in England midfielder Conor Gallagher came to nothing as Chelsea refused to allow him to join a top-six rival.
Howe, whose team host West Ham on Saturday, are third in the Premier League table, with just one defeat all season.
Asked at his pre-match press conference on Friday whether other clubs now see the Magpies as genuine competition, Howe said: "I think it is potentially difficult for us.
"It depends on the player and it depends on the club, but I think we're probably aware we are seen differently this season to how we were last season.
"We are viewed differently probably by some clubs now and that is something we will have to adjust to."
Newcastle beat Southampton in Tuesday's second leg of their League Cup semi-final to reach their first final since 1999 and keep alive their hopes of ending a trophy drought that dates back to 1969.
When Howe was hired in November 2021, just a few weeks after the Saudi-funded takeover of the club the previous month, he arrived to find Newcastle languishing in 19th place in the Premier League.
Having revitalised Newcastle with remarkable speed, Howe said the Magpies must now adopt a big-club mentality towards fighting on two fronts at the same time.
They are hoping to qualify for the Champions League via a top-four finish, as well as eyeing long-awaited silverware in the League Cup.
"It's about not getting carried away with that achievement in itself (reaching the final), it's about saying that was our expectation of ourselves before the game and we hit our expectations," he said.
"Now we shift our attention to a different competition we want to excel in. I don't think extreme emotions serve you that well."
Howe will have to do without the suspended Bruno Guimaraes against the Hammers, while record signing Alexander Isak continues to be assessed under concussion protocols following a blow to the head in midweek.