David Beckham was selected for the national team
David Beckham was selected on the national team

I think I personally will choose for to say that he was selected and become a part of the national team.
but I heard someone say on, can I use on?

Also, I'd like to ask if I can say change when the mood of a match or the situation of a match has turned around?

like saying.

"The situation has changed when David Beckham was sent into the game (David was reserved for the game, and then finally sent into it)"
"David Beckham has changed the match and now it seems that there are more likly for Machester United to score a goal and probably win over."
"The match has changed as Beckham is now playing a key role to boost the team's confidence"

I mean they are all in the similar context at the moment when the match is being played.

to my year, the first sounds completely natural but the second sound a bit tricky, it sounds ok to my ear, and the third does not sound ok, it sound really awkward a bit
I read in this situation "turn around" is a proper word to be said. is that correct?
if anyone can give me some detailed information regarding this matter, I would really appreciate it.

Kindly regards.