Tottenham have confirmed that defender Ben Davies is set to undergo surgery after fracturing his ankle in his side's 2-1 loss to West Ham. Pressure is mounting on Spurs boss Thomas Frank after a damaging home defeat to the relegation-threatened Hammers at the weekend. To make matters worse, Wales international Davies picked up the injury in the derby defeat and now he faces a lengthy lay-off.Callum Wilson's late winner at Tottenham Hotspur Stadium on Saturday condemned Tottenham to a Premier League home record of played 11, lost six, and won just two. Two days on, Spurs manager Frank is walking a tightrope to stay in his role, although the north London team are sticking with the ex-Brentford boss for now. The result means Tottenham are 14th in the table and have failed to win any of their last four matches. And going by the boos at full time, Spurs fans are far from happy with what they are seeing.On those boos, Frank said after the match: "It's not a nice feeling, but I understand the frustration. We are losing to a big London rival, there is nothing worse. We couldn't win at home, which we worked very hard to try to do that. Hopefully they [the fans] can see the effort from the boys, they are working very hard. We did everything in the second half."On Monday, Tottenham revealed that Davies will go under the knife later today for a left ankle fracture he suffered early in the West Ham clash. It remains to be seen how long the experienced defender will be out for but the club have wished him a speedy recovery.When Tottenham sacked Ange Postecoglou after he guided them to Europa League glory last May, they turned to Frank for a more pragmatic approach. But Spurs, who finished 17th last term, are in a similar position to where they were under the Australian at this point last season but instead of swashbuckling, and often kamikaze, football, the north London team are utilising a style that has flattered to deceive. Despite that, Frank still feels he has the backing of the club's board. He said on Saturday: "I am feeling the backing from everyone, everyone wants the same thing - long term success. We are doing a lot of things right behind the scenes, but we are not getting the results which is crucial."Despite that, he was well aware that the defeat to West Ham was not good enough and even admitted his side's ability to deal with set pieces is at an all-time low. "It feels like we've seen this before, like at Bournemouth when we do very well second half, get the equaliser and push for the winner, having chances and opportunities, but not getting over the line. Then we are stretched in the last moments of the game and lose 2-1," he said. "We started well in the first 15, then went 1-0 down. Then we rushed too much, gave the ball away too much, half-time helped, the boys pushed and did everything right. We scored the equaliser and created chances. It's super disappointing that we conceded in the last minute. If we can't win then we need to get the draw.Add GOAL.com as a preferred source on Google to see more of our reportingTottenham have a chance to bounce back quickly from this West Ham setback when they host Borussia Dortmund in the Champions League on Tuesday. Then, at the weekend, they travel to lowly Burnley in the Premier League. If he fails to win any of those matches, Frank could be out the job by next week.