[JRTJH]

Here's a diagram of the anode rod. It describes the condition fairly well. There's no need to replace a "worn rod" unless it's beyond at least 50%. Depending on the amount of use between now and the end of the season, your current anode may be more than you need for that time frame.

Keep in mind that the anode is the only protection your water heater tank has to prevent/slow corrosion. Once it's completely gone, the tank becomes the anode.