As well as snaring the mount on Native Soldier, on whom he won last time out at Caulfield in the Guineas Prelude, Allen will team up with Weir's Caulfield Cup fancy Night's Watch in the Caulfield Stakes and the Weir-trained filly Anjana in the Thousand Guineas.
Native Soldier has Sydney-trained The Autumn Sun to beat in the Guineas while the Kris Lees runner Smart Melody is all the rage in the fillies equivalent.
''I think it's definitely the biggest day of my career. The most I have ever had on the one day was just the one group 1 ride so I am looking forward to having three quality group 1 rides on Saturday,'' Allen said.
Native Soldier generally makes the running so drawing barrier four was just what Allen would have liked.
"I was happy with his barrier. As long as he jumps well he can get out quite comfortably and get a soft lead hopefully.
"I would say that the plan would be to lead if we can get there without doing too much work but if others want to go hard we can take a sit. Hopefully with The Autumn Sun's racing pattern we can get a break on him."
"I rode him first start and Weiry was happy with the way I rode him, then I got sick and that's when Dean Yendall ended up riding him. After he got beaten down the straight and he pulled up lame I was lucky enough to get back on him the next start. I don't know how it worked out, but I was just fortunate enough to get back on him and win on him.
"It's bit of a shame about the barrier draw for Anjana [gate 13] but in a big field, hopefully I can get her into a good spot.
"As long as there's a bit of give in the track that will suit her a bit better. She seems to get through the soft tracks better than the firm."