Biggest races where rider never competed
Major races where Diarmuid O'Brien never competed in.
| # | Race | Class |
|---|---|---|
| 1 | Tour de France | 2.UWT |
| 2 | Milano-Sanremo | 1.UWT |
| 3 | World Championships ME - Road Race | WC |
| 4 | Giro d'Italia | 2.UWT |
| 5 | Paris-Roubaix | 1.UWT |
| 6 | Il Lombardia | 1.UWT |
| 7 | Paris - Nice | 2.UWT |
| 8 | Liège-Bastogne-Liège | 1.UWT |
| 9 | La Vuelta ciclista a España | 2.UWT |
| 10 | Ronde van Vlaanderen - Tour des Flandres ME | 1.UWT |
| 11 | La Flèche Wallonne | 1.UWT |
| 12 | Paris - Tours Elite | 1.Pro |
| 13 | Gent-Wevelgem in Flanders Fields ME | 1.UWT |
| 14 | Tour de Suisse | 2.UWT |
| 15 | Amstel Gold Race | 1.UWT |
| 16 | Critérium du Dauphiné | 2.UWT |
| 17 | Tirreno-Adriatico | 2.UWT |
| 18 | Brussels Cycling Classic | 1.Pro |
| 19 | Volta Ciclista a Catalunya | 2.UWT |
| 20 | Omloop Het Nieuwsblad ME | 1.UWT |
| 21 | Itzulia Basque Country | 2.UWT |
| 22 | Donostia San Sebastian Klasikoa | 1.UWT |
| 23 | Tour de Romandie | 2.UWT |
| 24 | Giro dell'Emilia | 1.Pro |
| 25 | E3 Saxo Bank Classic | 1.UWT |