Cape Town - Rafael Benitez admitted his side struggled in their penultimate pre-season friendly defeat to Sporting Braga.
Newcastle United lost 4-0 to the Portuguese side at the Estadio Municipal de Braga on Wednesday night.
It was the Toon's first defeat of their off-season, having beaten St Patrick's Athletic 2-0 before drawing 2-2 with Hull City and 0-0 with Porto.
After the game, Benitez said: "It was a bad game for us, we're not doing well on the pitch or off it.
"It's concerning with the season 10 days away. That should be a wake-up call for everyone (at the club). If we don't improve everything we will suffer.
"The only positive was the attitude of the young players."
When quizzed about any potential new signings, Benitez added: "I said what I had to say on transfers two months ago, we'll see what the next 10 days bring.
"I have no idea. I have no idea how close we are to anyone.
"I said two months ago what we needed, and 10 days before the start of season we have four or five players we thought we could bring but we haven't - and we still are where we are."
There was no update from the manager on the expected swap deal involving Dwight Gayle and Salomon Rondon from West Brom, with Gayle reportedly eager to remain at Newcastle.
"Now is not a time to talk about [Salomon] Rondon or Gayle, it's a time to analyse what's gone on these last two months, added the manager.