Henry, 24, was named in the PFA Championship team of the year last season and has started all 15 Premier League games after helping Brentford win promotion.
Bees boss Frank said: “Rico has done fantastic so far in the Premier League. He had a little bit of a slow start, the first two to five games, but then I thought he really got up to pace.
“He also had a little bit of a staggered pre-season, so he’s in a really good place. He’s developing every single day and I’m pretty sure Gareth Southgate is very aware of Rico Henry.”
Henry, signed from Walsall as a teenager for £1.5million in 2016, is set to resume in Friday night’s home league game against Watford.
He has been capped at Under-19 and Under-20 level for England and despite the plethora of talented left-backs available to Southgate – Luke Shaw and Ben Chilwell were in his Euro 2020 squad – Frank believes Henry is edging closer to senior recognition.
“I can’t imagine anything else,” the Dane said. “I can only guess and look from the outside, and of course I’m only a tiny bit biased about my players.
“So I’m pretty sure Gareth and his staff are very aware of Rico, but they also need to be aware of a lot of other players.”
Frank also hailed another of his defenders, Charlie Goode, who has made the leap from Sky Bet League Two to the top flight in impressive fashion in little more than one season.
Brentford signed Goode after he had captained Northampton to promotion from the fourth tier in the summer of 2020.
The 26-year-old was restricted to just four starts in the Championship, but has begun the Bees’ last three top-flight matches.
Frank added: “Charlie deserves a lot of praise for his fantastic mentality. He’s always one of the best trainers.
“He’s been unlucky with so many different things, illness and injuries and Covid and so on. I don’t know how many games he played in the Championship, but it was very few.
“So if you jump from League Two to the Premier League, and now he’s just played three games in a row and I think he’s done well. They were solid performances and I’ve praised him for that.
“It’s a fantastic story for every football boy or girl out there that there is opportunity for all of us. Sometimes when it seems difficult, one day maybe you can play in the Premier League.”