Did Mike Modano ever wear number 39 if even for a brief moment at the start of his career?

Yes he did. He wore #39 in a pre season game in 1988 vs Dynamo Riga. It was his first game ever if you count pre season and he then went back to play one more year of junior. Dennis Maruk wore #9 with the North Stars at the time. Maruk only played 6 games with them that season and then retired. Modano returned to Minnesota to play in 2 playoff games against the Blues that season and wore #9 as a North Star for the first time since it was now vacant.