Mr Welch is the table tennis coordinator and says the worst injury he has seen is someone faint and hit the concrete wall behind them.
Heat exhaustion and dehydration are the most common problems, he said.
"Make sure you drink plenty of water. The game can stop if it means saving someone from getting injured."
More physically demanding sports such as mountain biking, indoor rowing or netball have a higher risk of injury, and these sports require a fully qualified paramedic in attendance for the Games.
As the competitors get older and push themselves harder, the risk of injury rises, Masters Games volunteer Brian Algar said.
"I can't think of specific cases, but I'm sure there have been broken legs and cuts and things." The Games run from February 1 to 10. They include 55 different sports with more than 2400 individual events. More than 4250 people have entered so far. Entrants take part in multiple events.