Tottenham Hotspur are awaiting the results of a second scan on Harry Kane’s ankle amid fears the England striker may have sustained ligament damage during the victory against Sunderland on Sunday, an injury that could sideline him for up to two months.

Kane, who scored the only goal of the game at White Hart Lane, fell awkwardly and twisted the joint late on and departed the stadium on crutches and wearing a protective boot on his right foot. Mauricio Pochettino conceded post‑match that the player may have sustained ligament damage, with medical tests duly undertaken on Monday. The results of a first scan at least reassured Spurs that the 23-year-old had not broken a bone in the fall.

However, there are concerns that Kane has sustained grade two ligament damage, which would normally require six to eight weeks of rehabilitation. Should the second scan confirm as much then the striker would miss the Champions League group games against CSKA Moscow and Bayer Leverkusen – Spurs lost their opening match 2-1 against Monaco last week at Wembley – and, among the seven Premier League fixtures within the timescale, key contests against Manchester City, Leicester City and Arsenal. The north London derby is on 6 November, towards the end of the normal recovery period for the injury.

While Spurs signed Vincent Janssen from AZ Alkmaar this summer, potentially to relieve the burden placed on Kane over the past few years, the player has yet to score in six appearances for the Premier League club, despite his prolific record in Dutch football. There would be an impact, too, on Sam Allardyce’s England national team, given Kane would miss the World Cup qualifiers against Malta and Slovenia next month, and the eagerly anticipated visit of Scotland to Wembley on 11 November. The striker was picked for the recent win in Slovakia, which kickstarted Allardyce’s tenure in charge.

Should the scan reveal only grade one damage then Tottenham would anticipate the absence of the player for closer to 10 days, a similar lay-off to that being endured by John Terry across the capital at Chelsea. That would represent good news. A grade three tear would represent a more serious scenario and a four-month rehabilitation, although Spurs are hopeful the forward has escaped that level of damage.

It remains to be seen whether Pochettino will risk starting Janssen in Wednesday’s League Cup tie against Gillingham, although the Dutchman has received backing from the captain, Hugo Lloris, to step into the breach. “We used to say that we have a competitive team and I think we are very confident in every player,” he said.

“When one player is missing, it gives an opportunity to another player to bring his skills, his energy, his qualities and his strength. This is the story of the season and that’s why we need all the players committed to the club. When the team needs you, you need to respond.”

Mousa Dembélé and Eric Dier limped out of the win on Sunday with cramp in their hamstrings. Dele Alli, who completed the game, has signed a new six-year contract at White Hart Lane. The 20-year-old signed a five-and-a-half-year deal when he joined from MK Dons in February 2015, with that now extended on improved terms through to 2022. He follows Dier, who agreed a five-year extension last week, in committing his future to the club.