André Villas-Boas defended Tottenham Hotspur's recruitment programme after they had been added to the list of Premier League casualties in the FA Cup and insisted he was comfortable with their attacking options despite going into the tie at Leeds United without a recognised senior striker.

Jermain Defoe has battled the pain of a niggling pelvic problem in recent weeks, which has required at least one injection and may yet need surgery to cure properly, and he was stood down from the 2-1 defeat at Elland Road. With Emmanuel Adebayor absent on Africa Cup of Nations duty with Togo, Villas-Boas was left to start two attacking midfielders, Clint Dempsey and Gylfi Sigurdsson, as centre-forwards.

Villas-Boas said that Defoe would return at Norwich City on Wednesday but there has been concern behind the scenes at Tottenham about the England international, even if the manager has been defiant in public. Defoe had been expected to miss the previous Sunday's home fixture against Manchester United only to declare that he was fit enough and determined to play.

The club have explored the possibility of signing a new striker this month, and Sevilla's Alvaro Negredo is the latest possible target. But Villas-Boas said that he did not foresee any reinforcements in the final week of the transfer window and he added that the apparent imbalance to his squad was not to blame for the loss to Leeds.

"It is risk we were willing to take," he said. "We are comfortable with the situation. We are happy with the squad. This defeat is not going to alert us to anything. Unfortunately we missed Defoe, who gives us options, but we have him back for Norwich and still have Ade to return so we have strength in depth.

"We will have to see when we can get Ade back but we did not lose because we missed chances that a striker may have taken. We lost because we could not create enough clear-cut chances.

"It's disappointing because we wanted to stay in this competition but they [Leeds] were very competitive and scoring first gave them the extra stimulus. Leeds made the most of their opportunities and deserve credit. We had a couple of chances in the beginning that normally we score and maybe we could have done a little bit more but it's a hard game for any team that comes here. Leeds were really up for it and going to 2-0 gave them more inspiration."

Neil Warnock, the Leeds manager, described it as a "fabulous day" for the Championship side. "We've got some good players. We haven't got a massive squad but when we play like we did today it makes me really proud to be the manager. We've had a few problems, a bit of dissent around the place. But I didn't think we got anything other than we deserved.

"When you look at the two teams on paper you don't know how the hell you are going to have a kick, let alone beat them. But you don't play teams on paper. It just shows what can happen if you've got a good group of players and you are all in it together."

West Yorkshire police confirmed after the match they were investigating a laser pen being shone from the crowd. Neither manager was aware of it but Warnock did mischievously suggest that "it must have been on their centre-half [Steven Caulker] for the second goal".

Warnock had left out Luciano Becchio because of his transfer request and confirmed there had been "two or three offers" from abroad but none that matched the club's asking price. Leeds, however, did not miss their leading scorer and Caulker was not alone in having a poor day. "My reflections on our defending I don't really want to make public," Villas-Boas said.