When asked about Alexander-Arnold’s omission, Tuchel said it was a “tough decision” to leave out the former Liverpool right-back.
“I know what Trent can give us and I decided still to stick to the players with us,” the England boss added.
He said players like Tino Livramento, Djed Spence and Jarell Quansah offered “a slightly different profile” to Alexander-Arnold.
Tuchel also explained it was a similar situation for Watkins, with Calvert-Lewin and Solanke selected over the Villa striker.
“I want to have a look at two other players to get a better picture and have a clearer opinion,” the 52-year-old German said.
Alexander-Arnold’s Real Madrid team-mate Jude Bellingham is included in the squad despite not playing for the club since early February because of a hamstring injury, while defender John Stones has made just two Manchester City appearances since early December.
Garner, who has started every game for the Toffees this season, said he was “really happy” about his first senior call-up.
“I was very confident it was going to come just on the basis that I’ve had a good season, so I finally got my chance and it’s a dream come true,” he said in a video posted on Everton’s X account.
Tuchel said: “A bit of an underrated player. He plays several positions. I’ve been impressed, watching him live, by his work rate and physicality. He is a fantastic team-mate and does a lot to help those around him.”
Meanwhile, England have said Steele, who has not made a single Premier League appearance for Brighton this season, is named “with the prospect of him joining the World Cup squad as a training goalkeeper during the summer”.
The call-up is the 35-year-old’s first at senior international level since he represented Great Britain at the 2012 Olympics in London.
Tuchel was also asked about Arsenal teenager Max Dowman, who became the youngest scorer in Premier League history earlier this month.
The England boss described the 16-year-old as an “outstanding talent” but said there was “no need to call him up now and increase the pressure”.
