Tottenham Hotspur technical director Johan Lange believes new signing Lucas Bergvall has ‘great potential’. Bergvall completed a switch to Tottenham earlier this month and will officially link up with Ange Postecoglou’s squad at the end of the season. Spurs hijacked Barcelona’s move for the Swedish starlet, with Dejan Kulusevski also playing a role in convincing Bergvall to make the move to north London. Spurs fans will be forced to wait until next season to see the Djurgarden midfielder in action. But one of the men responsible for signing the youngster, Johan Lange, has offered an indication…