不用改，现在就有规则的。

www.ausopen.com/en_AU/event_guide/a_z_guide.htm

lInjuries

A player who sustains an injury during play may request the umpire to call a trainer, who assesses the injury and informs the umpire whether a medical time-out will be taken.

If a player carries an injury into the match, treatment is limited to the normal changeover period, unless a further aggravation occurs during play.

Medical time-out

The provision of both evaluation and treatment of players for injuries and medical conditions during matches. Actual treatment time is a standard three minutes.