Bale has been included despite having asked not to be involved in Madrid's game at Manchester City earlier this month.
Zidane, whose team lost the game and were knocked out by City, claimed Bale had requested to be omitted and the 31-year-old has played just 110 minutes since February.
The likelihood of him taking to the field for Madrid with any regularity next season appears remote – even though Bale is under contract until 2022 – while the 31-year-old's wages and hefty transfer price remain stumbling blocks for a move elsewhere.
However, he remains integral to his country's cause and will be expected to start for Wales when they play Nations League fixtures against Finland and Bulgaria next month.
"I've always said ideally you want the players playing," Wales boss Giggs told FAWTV. "You want them playing regularly so when they come into camp, they're in that match rhythm. You don't always get that and it's something I've become used to and you have to manage it right.
"Gareth played every game in the [Euro 2020] qualifiers but wasn't playing regularly for his club. I'm used to dealing with that situation."
Liverpool youngster Neco Williams has been called up to Giggs' squad for the first time, while there is also a place for Euro 2016 striker Hal Robson-Kanu for the first time in three years. The West Brom forward had previously announced his international retirement but reversed that decision earlier this year.
Wales squad: Wayne Hennessey (Crystal Palace), Danny Ward (Leicester City), Adam Davies (Stoke City); Ashley Williams (unattached), Ben Davies (Tottenham), James Lawrence (Anderlecht), Ben Cabango (Swansea City), Tom Lockyer (Charlton Athletic), Neco Williams (Liverpool), Chris Gunter (unattached); Connor Roberts (Swansea City), Ethan Ampadu (Chelsea), Will Vaulks (Cardiff City), Matthew Smith (Manchester City), Joe Morrell (Bristol City), Dylan Levitt (Manchester United), Daniel James (Manchester United), Jonny Williams (Charlton Athletic), Rabbi Matondo (Schalke), Aaron Ramsey (Juventus); Gareth Bale (Real Madrid), David Brooks (Bournemouth), Harry Wilson (Liverpool), Kieffer Moore (Cardiff City), Hal Robson-Kanu (West Brom), Tyler Roberts (Leeds United).