The Icelandic midfielder, who joined from Hoffenheim this summer, came on at half-time before scoring 10 minutes later and although he admits it was nice to score, he is hoping he can continue that form into the season proper which kicks off on August 18.
"It was very nice to get a goal but I think the most important thing is getting used to playing football again," Sigurdsson told London24.
"It's always nice to score. It probably would have been better to score in the Premier League but it was good to get my first goal of the season and it will give me confidence for the next couple of weeks.
"I'm off the mark, but in a friendly it doesn't really matter.
"There's no point scoring in the friendlies if you don't score in the league, so as long as I'm getting close to full fitness, and getting fitter and stronger every week, that's the most important thing."