O'Connor has been training at 10 and 12, sharing the duties with English import Danny Cipriani and James Hilgendorf.
The Rebels also face trials against two other New Zealand teams - the Blues at AAMI Park on Saturday February 11 and then the Crusaders a week later at the same venue.
Their first Super match is against Beale's old team, NSW, at AAMI on March 2.
"Hopefully, the first two trials will answer a lot of questions regarding combination and where players are at with their skill level and, in the third trial against the Crusaders, we'll still play a squad but it will be closer to what we'll end up with against the Waratahs.''
Hill took over as head coach from Rod Macqueen for this season and said he was happy with how his side was shaping up.
He made special mention of the pre-season efforts of his young front-row combination of Laurie Weeks and Paul Alo-Emile, who will need to step up after the retirement of legendary prop Greg Somerville.
The 20-year-old 120kg Alo-Emile spent a year with the Western Force before joining the Rebels but has yet to make his Super Rugby debut.
"Training is going reasonably well but there's a lot of hard work to be done between now and when we play the Waratahs,'' Hill said.
"I think we're chipping away and I'm happy with the way we're progressing.''
- AAP