"I don't care if you dump it in the middle of a park, somebody is going to find it and hand it in.
"That is all we care about - just return the kit so we can play our season."
The car was broken into sometime between 9.30pm on Saturday and Sunday morning.
The club's premier men's team had earlier enjoyed a successful away trip to Gisborne, recording a big win, before returning home in a hired team bus.
After having a few drinks on the trip back to Napier, taxis were ordered to take some of the players home from the Port Hill clubrooms so they wouldn't have to drive.
The kit bag and other items were placed in a locked car.
Thompson said a lot of work had gone into securing sponsorship this year to help the club cover costs, and different sponsors had been printed on each jersey.
"It is not something you just buy off the shelf, it's something that you actually have to go and spend money on to be put on the kit. So it's all personalised.
"For all that hard work to go to waste for someone just to throw it in the river or burn it is very disheartening."
The men's side had to play in an away kit on Monday during a cup game.
As of Monday afternoon, the home kit had not been returned.
Police are asking anyone with information about the theft to contact them on 105 and quote 220605/8369.