The South African may not be granted a work permit to continue playing in the UK.
Dickov admitted he wanted to sign the South African, but made it clear that red tape might force him out of a move:
“I’ve been in contact with his representatives and the problem that Bongs has got at the minute is his working visa in this country.
“Bongs was fantastic for us, on and off the pitch, as a player and a person.
“He would definitely be one that we’d be interested in.
“I made the call to his agent at the end of the season just to find out what he was thinking because he finished it really strongly at Colchester.
“We were told then the main problem would be the visa and that’s an ongoing thing at the minute, and it’s still a problem for him.
“That’s not just disappointing for me but for Bongs too because he wants to stay in England.”
Khumalo of course has played for Doncaster before. He was on loan at the Keepmoat Stadium from Spurs in the 2013-14 season, before a knee injury ended his time in Yorkshire prematurely in March 2014.
He spent the end of last season on loan in League One with Colchester United, helping the club to survival in their relegation battle with several solid performances at the back.
However Khumalo has not played for South Africa since a 5-0 loss to Brazil in March 2014, making obtaining a working visa very difficult for the player.
Tottenham snapped up the then 24-year-old South African centre-back in January 2011 from Supersport United. The defender had impressed the previous summer for Bafana Bafana at their home World Cup - even scoring in their 2-1 victory against France.
Khumalo has been out on loan four times since being with Spurs, to Preston North End, Reading, PAOK Salonika and of course Doncaster and Colchester. However, in his four years at White Hart Lane, he has never made a competitive appearance.
The last time he featured in a match-day squad for Spurs was way back in April 2012 for a fixture against QPR in the Premier League.
But he still remains an icon for many Spurs fans because of his excellent performances for the under-21 side and his humility in isolation from the first-team.
Tottenham fans would be the first to congratulate Khumalo if he did make the move to Doncaster and the most upset if he was forced abroad.