Roberto De Zerbi believes that saving Tottenham Hotspur from relegation is “the biggest achievement” of his managerial career.De Zerbi’s Spurs completed their rescue job on Sunday by beating Everton 1-0, their third win in the last five games. They finished in 17th place, two points ahead of relegated West Ham United, vindicating Spurs’ decision to hand De Zerbi a five-year deal at the end of March.“It is the biggest achievement in my time,” De Zerbi said in his post-match press conference. “Brighton in the Europa League was great. The second place in Marseille with a lot of problems was a big achievement. But I think today was maybe one of the best days in football.”De Zerbi will now start the process of planning next season and he said that there will have to be changes to get Spurs back to the level they want to be at.“We are Tottenham, and we can’t suffer like this until the last second of the last game to stay up,” he said. “I will be stronger. I don’t want to decide alone, because football is a group. Sporting Director, scouting, CEO. But my target now is finished to stay up. My target is to start the pre-season with the team I have in my dream my head.” De Zerbi said that Spurs have “10, 11, 12 good enough players” but that he wants to complement that group with “first-level players” coming in.But De Zerbi said that people must be aware of what went wrong this year and make sure this is not repeated again. Spurs finished 17th for the second season in a row.“It’s difficult to promise because the Premier League is very tough,” he said. “For sure, we have to learn from our mistakes we have done this season. But no, ‘Now we are happy because we stay up and we forget the past.’ No, no. Stupid people forget the past. Smart people, the people with value, can’t forget and keep in their mind the past, and we have to improve from our mistakes, and we have to look forward to start to rebuild a team from this night. From tomorrow. Not from 10 days. We have no time to go on holiday.”De Zerbi praised the efforts of multiple players after the match, including goalkeeper Antonin Kinsky. The 23-year-old started Tottenham’s last seven games after Guglielmo Vicario underwent hernia surgery. The run of starts came after Kinsky made two mistakes leading to goals and was substituted after just 17 minutes in a 5-2 defeat against Atletico Madrid in March.“I want to say a secret. Before my first game in Sunderland, I thought to make Kinsky captain for one game, to show one thing that’s very important in football and life,” De Zerbi said. “If we’re a team, we’re like a family. If one of us is going through a difficult period we have to stay with him, showing love and everything he needs, but he didn’t need. Because he’s a strong character. Strong personality. A great goalkeeper.”