I hired Robin Söderling when he was 17, but he had turned pro and I hired him with a pro tour goal getting a higher rank. However, he still was entered into some junior tournaments (I'll assume from the year before, it was week 1 when I hired him). In case it is of any relevance, my starting player began at pro age. Whenever Söderling went to travel to a junior event the next week, the game crashed.
It is also worth noting that there has always been an issue when hiring new players; tournaments they are entered into for the next few weeks aren't shown in the planning submenu.