I usually suggest to test players vs a 1% team to oversize the internal programming and expose the player power... but today I'll suggest you a different experiment for the defender, and is to face a +2* team, because the worst thing you can have in defense is a contributive player giving you bad actions, or a neutral player giving a negative impact to your team.
By facing a 1* team you can not expose a defender to know if he is aggressive, or even to know if have some bad animations/actions associated to him.
Ofc. if he earns a 8-9-10 in the friendly vs a 1* it should be a good sign, but by facing a +2* team the defensive actions will emerge without your team being neutralized due AvQ margin (so face a +2*, not a 180% team as this will add more players in the defensive list of animations).
Try this because for sure that can be a good experiment
Too you can see if he defends corners and FKs in both cases with a different opponent AvQ criteria, and if he joins the attack, ofc. you can place him to pick corners and FKs and test**