The Magpies have a deal in place with AC Milan for Tonali and have been rushing to push the capture of the midfielder over the line.
Officials have headed to Italy Under-21s’ camp in Romania and have been putting Tonali through his medical paces.
However, there could well be a delay to Newcastle completing the deal.
There remain some details to finalise with AC Milan which mean that the operation could extend over the weekend.
While there is no suggestion that Newcastle could miss out on Tonali, it appears that the club will have to wait a little longer to formally push his capture over the line.
Tonali is expected to head off on holiday once he finishes international duty with Italy Under-21s.
Then he will link up with Eddie Howe’s side to begin preparations for the new season, which will also see him turn out in the Champions League with Newcastle.
