Having moved to the North London side from Bundesliga club RB Leipzig for a reported fee of 60 million euros (£51m) in August, the 22-year-old Netherlands international has one assist for Spurs, which came on his debut in September's 3-0 win over West Ham United.
"Xavi has been with us for seven or eight weeks, which is a short time in football but also a long time," Frank told reporters on Friday.
"I liked his personality after the first 60 minutes against (Aston) Villa, but he then tired a bit.
"Our demand to him is more intensity, but a player I believe in, he's got the pass and vision.
"We've just been training and he trained very well."
Another new arrival, French forward Randal Kolo Muani, is edging closer to his first Premier League start since joining Spurs from European champions Paris St Germain on a season-long loan deal in September.
The 26-year-old made his Premier League debut in Spurs' 2-1 home defeat by Villa on Sunday, after being out with a "dead leg."
"It's the first time he's had a sustained block of training and minutes. He can't be bombarding 90 minutes again and again, but he can be used, which is good news," Frank said.
Spurs are sixth in the league table with 14 points from eight matches, trailing leaders Arsenal by five.
Frank's side are looking to get back on track when they play 12th-placed Everton, having lost to Villa and drawn with AS Monaco in the Champions League.
"I think Everton is a very good team, not just (Jack) Grealish. A good colleague and friend of mine, David Moyes, is there - someone who I respect a lot, and his teams are always hard to beat. He has got Grealish able to flourish again," Frank said.
Spurs will be without captain Cristian Romero for the Everton trip as the Argentine centre back recovers from an adductor strain.
"Cuti (Romero) just walked out on the grass running, positive and progressing, no time frame, but I don't expect it to be a longer one," Frank said.
"Destiny (Udogie) isn't on the grass yet, not a longer one.
"Dominic (Solanke) positive, he's taking steps in the right direction every day."