2006-07: Deilert, still within Djurgarden’s system, spent the season with each of the team’s U18 squads and its U20 squad, where he tallied a goal and five points in 28 games. He competed with the Swedish National U18 Team, tallying an assist in 10 games of international play.
2007-08: The defenseman again spent the season with Djurgarden U20 (SuperElit), this time netting a career-high six goals and 18 points in 38 games; Deilert’s 70 penalty minutes were another personal best. He also competed with the Swedish National U19 Team, but failed to register any points through eight games.
2008-09: Deilert spent the season with Djurgarden U20 (SuperElit), netting four goals and 11 points, along with 45 penalty minutes. He also saw time with Almtune (Allsvenskan), tallying an assists in six games, and added another five points (1g+4a) in eight games with Frisk Asker (Norway). He again competed with the Swedish National Team, this time with the U20 squad, where he registered four assists in four games on the international circuit.