We have data like the ones you are interested in for players, but at the moment we have published them only for national leagues (ULTRA and MEGA plans), see for examples the player details API here
https://rapidapi.com/heisenbug/api/premier-league-live-scores?endpoint=57b4bf90e4b01bbb07703f18
where you can find sample response data for the Liverpool’s player Mohamed Salah

{“playerName”:“Mohamed Salah”,“age”:25,“position”:“Forward”,“nameInCountry”:“محمد صلاح”,“nationalities”:[“Egypt”],“shirtNo”:“11”,“foot”:“left”,“marketValue”:"80,00 Mill. € ",“playerAgent”:“SPOCS”,“inTeamSince”:“Jul 1, 2017”,“contractUntil”:“30.06.2022”,“presences”:31,“asFirstEleven”:29,“minsPlayed”:2484,“yellowCard”:0,“redCard”:0,“goal”:29,“currentNational”:“Egypt”,“nationalPresences”:56,“nationalGoals”:32,“outfitter”:“adidas”,“twitter”:“http://twitter.com/22mosalah",“facebook”:“http://www.facebook.com/momosalah”,“instagram”:“http://www.instagram.com/mosalah22/”,“active”:"true”}

In European Cups, there are players from many national leagues we are not following at the moment, so retrieve data for them could be a little challenging, however, I’m going to check if there is any change to add them for Champions and Europa League in a week or two, maybe in a lighter form with not all the data we usually have, as in the example.
Stay tuned.
bye

In your player statistics you separate the stats by fixtures which is perfect for our application. However we notice that there isn’t an endpoint for just the players and their information. We want to build a library of all of the players in champions league and be able to sort them by their teams, each Match Day statistics, total Match Day statistics, etc.

For example:

“player_id”:253
"player_name":“Alphonse Areola”
“firstname”:“Alphonse”
“lastname”:“Areola”
“position”:“Goalkeeper”
“age”:26
"birth_date":“27/02/1993"
“birth_place”:“Paris”
“birth_country”:“France”
“nationality”:“France”
“height”:“195 cm”
“weight”:“94 kg”
“team_id”:85
"team_name”:“Paris Saint Germain”
“league”:“Champions League”
“season”:"2019-2020"
“Match Day”: "1"
stats(all stats from Match Day 1)

We really like your endpoint format “player stat per match”. Is there a way you can allow us to call all players involved in the tournament with player_id, team_id, etc. If you would like we can speak with you in more depth via email. Would you be able to speak to us privately? We would really appreciate your time to help solve this issue. email: myteamfcapp@gmail.com

Hi,
we are going to release some new APIs in a few days, and in these, we could add one on player data, could you provide an example of the response you are interested in so we can evaluate if this new API could be what you are searching for?