Theo Walcott has reflected Arsenal's confidence before Saturday's showpiece FA Cup tie by telling Tottenham Hotspur it is a "bad time" to visit the Emirates Stadium.

Tottenham are buoyant under Tim Sherwood, having won 2-1 at Manchester United on New Year's Day. They have taken 10 points from an available 12 in the Premier League since Sherwood replaced André Villas-Boas to sit two off the Champions League places and eight off the top. Sherwood has unlocked something in a squad who had come to labour under Villas-Boas.

It is Arsenal, though, who are setting the title pace. Since the opening day defeat against Aston Villa, they have won 10 of their 14 home matches in all competitions, with two defeats coming against Borussia Dortmund in the Champions League and Chelsea in the Capital One Cup.

Walcott was asked whether he considered it to be a bad time to face Tottenham, given their revival under Sherwood. "It's going to be a bad time to play us as well," he replied. "For the neutrals, it's going to be a very interesting battle. I can't call it. It's one of those games that's going to be very open. The FA Cup is always special for me, being English. I love the FA Cup.

"Since their new appointment, Tottenham have done very well, to be fair to them. But like I say, they won't want to play us. And it's at the Emirates. We're trying to make our stadium into a fortress and we are starting to do that."

For Walcott, the excitement is palpable . It will be only the sixth time that the clubs have met in the FA Cup. "The first fixture I always look at is Tottenham," Walcott said. "Every time Tottenham come here or we go there, you want to put 100% in. These are massive games."

Walcott traced Arsenal's upturn in 2013 to the league defeat at Tottenham on 3 March. In the following game, they won at Bayern Munich in the Champions League and, although it was not enough to avoid a last-16 exit on away goals, it was the prompt for a strong finish to the domestic season. The team have maintained the momentum over the first half of this season.

"Ever since that Bayern Munich result, really … it's changed the whole club," Walcott said. "Since then, we've showed great consistency throughout, not just scoring goals but keeping clean sheets. If you're going to win titles, you've got to keep clean sheets. We always know we're going to score goals; it's been the problem of conceding them but everyone's been doing their jobs right and it's important for the team."

Walcott has been in form since his return from an abdominal injury, which required surgery and was complicated by a reaction he suffered to antibiotics. He was out for just over two months and made his comeback as a substitute against his former club Southampton on 23 November. Since regaining his starting place at Manchester City on 14 December, the forward has scored five goals in five matches.

"I missed so many games and it's been so frustrating," Walcott said. "But I'd rather that injury happened at the start of the season than come in the middle or at the end. It was always going to be a slow process and I had a bit of a reaction to antibiotics I took which delayed every-thing. It's all going well now and I am very happy."

Walcott said that many of the team in the New Year's Day home win over Cardiff City were at "90% [fitness]," with him being one of them owing to a shoulder complaint. Arsène Wenger would like to make wholesale changes for the FA Cup third round tie but the identity of the opposition makes that problematic.

Wenger will be without Mesut Özil, Aaron Ramsey, Olivier Giroud, Nicklas Bendtner and Kieran Gibbs, plus the long-term casualties Alex Oxlade-Chamberlain, Abou Diaby and Yaya Sanogo. He will consider whether to name midfield prodigy Gedion Zelalem in the squad after the 16-year-old has trained with the first-team this week.

"Wins like Cardiff prove we are serious contenders," Walcott said. "With every win, the belief gets stronger and stronger. A lot of people are not giving us enough credit but we don't mind that. We just carry on with our job."