what's a word/phrase that describes unwillingness to share advice (such as strategy on how to improve in a sports match)?

I'm having trouble coming up with a word/two-word phrase describing unwillingness to share advice (such as strategy on how to improve in a sports match)? May someone help?

I'm hoping that this would either be one word or two words.

Uncooperative

unwilling to help others or do what they ask.

Close-lipped here:

inclined to secrecy or reticence about divulging information;
"although they knew her whereabouts her friends kept close about it"

Secretive; uninformative; obfuscatory (though the latter would mean they're deliberately clouding the picture). Can't think of anything that's exactly what you want though.