Eddie Howe conceded Newcastle United could not control the "forces that are at play" over Bruno Guimaraes' future at the club amid interest from Arsenal.
Guimaraes is expected to return to Newcastle this Friday following an extended summer break after playing his part in Brazil's run to the round of 16 at the World Cup.
The 28-year-old has been the subject of interest for Premier League champions Arsenal, though a bid for Guimaraes has yet to be tabled by Mikel Arteta's side.
It has been reported that Arsenal are preparing an offer of around £80m to secure the services of the Brazil international.
Guimaraes joined Newcastle from Lyon in 2022 and has gone on to make 195 appearances across all competitions, scoring 31 goals and providing 31 assists.
He also captained Newcastle to their first domestic trophy in 70 years in the EFL Cup final last March, though his time at St. James' Park could be coming to an end.
Last summer saw Alexander Isak fail to join up with Newcastle's squad to force a move to Liverpool, and while Guimaraes was an internal critic of his former team-mate, he now finds himself in a similar position.
And Howe could not offer any clarity on the situation ahead of his planned return, telling reporters at Ashton Gate following Newcastle's 4-1 defeat to Bristol City in a pre-season friendly on Wednesday: "Any distraction, if it's not healthy, is unhealthy.
"So, yeah [it would be negative for the speculation to drag on]. But we're not in control of that.
"And to some degree, I don't think Bruno's in control of that either. What will be, will be. We can't control the forces that are at play here.
"We've just got to make sure that when Bruno comes back, we look after him and he trains well, which I'm sure he will do. And he makes a difference, as he always has done."
Full-time in Bristol.
— Newcastle United (@NUFC) July 29, 2026
Thank you to the 3,400 Geordies for your backing at Ashton Gate this evening. Safe journey home pic.twitter.com/RT7kNEAOR4
When asked directly if Guimaraes will be joining up with the squad on Friday to travel to Spain, Howe said: "The details I don't actually know, but I don't see any reason why that wouldn't be the case."
Howe's comments came after he watched his side get comfortably beaten by Championship opposition Bristol City, despite fielding a number of first-team players.
Sam Greenwood opened the scoring in the 26th minute with a stunning free-kick past summer signing Ewen Jaouen before Lorent Tolaj muscled his way past Sven Botman and picked out the bottom-left corner three minutes later.
Jacob Murphy's loose pass in the 50th minute was then ruthlessly punished by Max Bird's inch-perfect finish after he was found by Jason Knight, though Harvey Barnes was able to pull one back for Newcastle 12 minutes from time.
However, Sam Bell's dangerous ball into the penalty area was turned into his own net by Botman, with Newcastle finishing the game with an expected goals (xG) total of 0.98 from their 15 shots, though only three were on target, compared to Bristol City's tally of 0.38 from their six attempts.
"I actually thought it was a pretty strong performance, despite the fact that the goals we conceded were bizarre," Howe added.
"Pre-season is to get out all the rustiness of the summer, to get the players to a position where, when the team faces Liverpool, they're ready."
Newcastle face Valencia, Everton, Bayer Leverkusen and Strasbourg before beginning their Premier League campaign at home to Liverpool on August 23.