The Gers were beaten 3-1 at Ibrox by the Scottish Premiership club on Tuesday night.
The 24-year old was instrumental in St. Johnstone’s high-intensity start, and has his pace proved a problem for the Gers backline for much of the game.
He grabbed his side’s third goal early in the second half to effectively kill off the game, and suggested afterwards that Rangers had failed their first real test of the season.
“Rangers are doing well in their division but we proved a different test for them. We have a lot of quality,” said O’Halloran, in quotes published by the Daily Record.
“The pressure was on them. We knew we had good quality players in there who could hurt them.
“I don’t think they have really been tested. There are a lot of teams we feel give them a lot of respect.
“Obviously we were aware of them but we knew if we played our game we could go out and hurt them,” he added.
Rangers have built up an almost unstoppable aura among their Scottish Championship rivals after collecting 11 wins from 11 before last night’s game.
The fear factor clearly doesn’t extend to top-tier opposition, however, and St. Johnstone brought Mark Warburton’s team back down to earth with a perfect away performance.
Speculation as to how this current Rangers team would fair in the top flight has led some to suggest they would challenge for a European position, but on the evidence of last night, that’s unlikely to be the case.