If they play well on court, it doesn't matter if they don't fraternize off it.
From the usatoday.com
Make it a rule to not fraternize with your employees, and choose your partners wisely.
From the forbes.com
Do not fraternize with your employees, and choose your partners wisely.
From the forbes.com
Practice is his only opportunity to make a contribution and fraternize with his teammates.
From the boston.com
That is one reason you seldom see them fraternize with the opponent.
From the post-gazette.com
How could a couple touched by the Holocaust fraternize with one of its apparent architects?
From the sacbee.com
As most teams did, the Orioles in those days would fraternize with opposing players before games.
From the orlandosentinel.com
For enthusiasts, the events are sport, an opportunity to fraternize with others who love cars and speed.
From the washingtonpost.com
Officers are not permitted to fraternize with enlistees.
From the time.com
More examples
Be on friendly terms with someone, as if with a brother, especially with an enemy
Fraternization is "turning people into brothers" - conducting social relations with people who are actually unrelated and/or of a different class (especially those with whom one works) as though they were siblings, family members, personal friends or lovers.
(fraternization) The act of fraternizing or uniting as brothers
(FRATERNIZATION) to consort or associate cordially with members of a hostile group is strictly prohibited; as between enlisted and commissioned RANKs, between male and female MIL-PERS, between constabulary and civilians in occupied or pacified territory. ...