Rather than requiring a team-up (which is a logical counter-argument to this suggestion):
What if another available boost to draw from would be to allow the player to have a 10% ‘boost of health’ added to their health bar to start a match. (So a character that normally has 6,800 health starts a match with 7,480.) A fixed value of additional health could work, but feels too much like a “hot-dog stand” if it is too low. (oh environment tiles, how I miss you.)