Forward McKirdy joined Swindon at the start of the season and is the club’s top scorer, with 14 goals in 32 appearances, including one in the team’s third-round FA Cup defeat by Manchester City at the County Ground in January.
Swindon are due to play League Two leaders Forest Green Rovers at home on 26 March.
Rovers chairman, Dale Vince, wrote on social media that they would pay for Joe to be a mascot for Swindon for the match if he can be found.
“Stories like this must unite fans,” Vince wrote.