Brennan Johnson has scored two goals in 18 appearances for WalesWales boss Robert Page struggled to hide his disappointment after ruling forward Brennan Johnson out of contention for Euro qualifiers with Croatia and Latvia.
Page says Johnson has not reported for international duty this week.
The Wales boss said he was unhappy with how the injury had been handled and suggested Johnson had been let down.
"First and foremost I feel for Brennan. He wants to play international football like everybody else," Page explained.
"As we know, playing for your country is something very special, it shouldn't be taken for granted, by anyone.
"Everybody who has got a responsibility for Brennan should respect that and help him in any way they can. But it is what it is, we've got to pick a team to go out compete against a very good team."
There had been fears around the 21-year-old's fitness after he picked up a groin injury on 11 March, before playing a full 90 minutes six days later against Newcastle United.
Page says he regrets not fighting to have Johnson to report to camp for an assessment and says Forest having a Welsh manager in Steve Cooper has proved to be a non-factor.
"We were aware of something last week and then he went and played 90 minutes on the Friday and wasn't available to meet up on the Sunday," Page told BBC Sport Wales.
"Like I said, everybody's responsible for him. It's very special to be in that changing room and play for your country. You shouldn't take that for granted. The people responsible for him shouldn't take that for granted and should appreciate and respect that as well.
"It is not about him being a Welsh manager, he could be English, Scottish, it doesn't matter about the nationality.
"He's got a job to do. I'm thinking of the player.
"We've got to respect it's an unbelievable honour to play for your country.
"Where I should have been a little bit stronger is with getting Brennan through the door on Sunday to assess him."
Croatia host Wales on Saturday at the Stadion Poljud (19:45 GMT).
Wales were already preparing to field a new-look team after a whole host of injuries and retirements.
They are beginning life without their men's top goalscorer and greatest modern day footballer - Gareth Bale.
Joe Allen, Chris Gunter and Jonny Williams followed Bale in announcing their decisions to call time on their international careers.
On the injury front, Tottenham defender Ben Davies has withdrawn from the squad with a suspected hamstring problem, while Johnson's team-mate Wayne Hennessey is also unavailable.
In total there are seven uncapped players in Page's squad - Morgan Fox, Tom King, Jordan James, Nathan Broadhead, Luke Harris, Oli Cooper and Liam Cullen.
With Johnson sidelined, Wales will most likely have to field a forward line comprised of players struggling for minutes at club level.
Fulham's Harry Wilson and Daniel James have one start between them in 2023, and have totalled just 196 minutes of football in that time.
Bournemouth striker Kieffer Moore has played just one minute since starting against Nottingham Forest on 21 January.
The most in-form forward available to Page is Millwall's Tom Bradshaw, who is back in the Wales squad for the first time since March 2018.
Bradshaw has scored 14 goals in the Championship, including two hat-tricks, winning the division's player of the month award for February.
