LONDON -- Tottenham manager Mauricio Pochettino was unimpressed with his fringe players in Saturday's dramatic 4-3 win against Wycombe Wanderers in the FA Cup and warned: "If you cannot play in this type of game, we will have a problem."

Before the game, Pochettino told his second string they were playing for their "long-term futures" at the club and made nine changes from the side that drew 2-2 at Manchester City last weekend, with only Eric Dier and Kevin Wimmer keeping their places.

But Pochettino was forced to make three substitutions before the 60th-minute and it took a goal from Son Heung-Min in the final minute of stoppage-time to finally break the League Two side, who led 2-0 at half-time and 3-2 after 83 minutes.

Paul Hayes' double, the second from the penalty spot, put Wycombe in charge but Son pulled a goal back and then Spurs' substitute Vincent Janssen won and scored a penalty. Garry Thompson's header seven minutes' from time put the visitors on course for a famous victory but Dele Alli, another substitute, equalised two minutes from time before Son wrapped up the win.

"Full credit to Wycombe and how they played the first half. They were better than us. You know we are a team that is involved in different competitions and I think that if you sign for Tottenham, you are in the squad for Tottenham," Pochettino told a postmatch news conference.

"If you cannot play in this type of game, then we will have a problem. Full credit to Wycombe though, they played well and found a way to create chances."

Spurs played the final half an hour with 10-men after Kieran Trippier hobbled off in tears with a hip problem but Pochettino said he had not had a chance to assess the defender.

"It was difficult in the first half and it's true that in the second half we increased our level. I think we turned the result around and then to play the last 30 minutes with one less I think is another positive to take," he added.

Tottenham were not at their best. Andrew Matthews/PA Images via Getty Images

Pochettino's Tottenham have been eliminated from the fourth and fifth round of the FA Cup in his two previous seasons at the club but the Argentine said he was finally starting the appreciate the magic of the competition.

"Maybe that is the beauty of the FA Cup and the different levels of the teams," he said. "Maybe they showed similar potential and quality [to us], but that is the magic of the FA Cup.

"This is the FA Cup. It was difficult for me from day one when I arrived [in England] four years ago to say, 'Oh the FA Cup is beautiful or the FA Cup is magical.' Now I realise that it's a special competition. It's the most special competition in the world. You cannot replicate the same passion in Spain, France or Italy or the atmosphere on the pitch.

"You get the small sides like of Wycombe with players from League Two who are exciting and they believe that they can beat us here. That is the important thing that the FA Cup creates, that feeling. It's fantastic. I'm very touched by it.

"They showed that they are very sad now and disappointed. We can do nothing about that. That's football. Today it was for us and maybe another day it is for them. But I wish them all the best in their league and it was a pleasure to play against a team like Wycombe."