The Hibernian winger is in career-best form after recovering from two serious knee injuries, underpinning his performances with six goals in 12 appearances this season - four of which have come in the last three games.
He was voted the Scottish Premiership’s player of the month for December and is coming nicely to the boil ahead of March’s Qatar qualifiers against Kuwait and Nepal.
For Arnold, Boyle’s eye for goal - he has scored twice in four appearances for his adopted country - is a Godsend, and adds another threat in the final third to that already posed by the likes of Adam Taggart, Mathew Leckie, Jamie Maclaren and Apostolos Giannou.
“Look, we haven’t seen a lot of Martin so far with the national team because of a few setbacks,” Arnold said.
“But we knew a lot about him before he opted to play for Australia (over birth country Scotland) and he’s just getting better and better.
“He’s a big asset for us because he can open things up with his attacking runs in behind, and his ability to beat a player with his speed and a bit of trickery.
“He also has a knack for picking the right pass or cross.
“Then on top of that he’s got this instinct for finding space in and around the box where he can finish things off. That goalscoring side to his game adds another dimension.
“That’s not something you can really teach - but he has it in spades.
“For any coach, having a player who offers so much and poses such a threat, it’s a blessing.”
Arnold is in close contact with the 26-year-old between international call ups, sharing texts and offering encouragement during the good and bad times where injuries were an unwelcome companion.
He doesn’t resile from the fact that Boyle’s absence from January’s AFC Asian Cup was costly, after a debilitating knee injury suffered in the final warm-up game against Oman rubbed him out of the tournament.
His pace, penetration and finishing prowess were sorely missed - along with the unavailability of Aaron Mooy and an underdone Mathew Leckie - as Australia bowed out at the quarter-final stage in the UAE.
Arnold welcomed Boyle back for Australia's 1-0 victory over Jordan in Amman last November, where he made a 17-minute cameo off the bench.
Boyle, whose contract at Easter Road runs until mid-2021, is rumoured to have caught Celtic’s eye with his recent goal spree and, on current form, is likely to be a first choice for Australia in March.
“It’s really gratifying to see him back injury free and enjoying his football,” Arnold added.
“He’s playing with a lot of freedom and hunger and that’s all any coach can ask for.”
Arnold is currently in Bangkok fine-tuning the Olyroos’ preparations for Thursday's (AEDT) AFC U-23 Championship semi-final against Korea Republic, with a third-placed finish at the tournament also guaranteeing qualification for July’s Olympic Games in Tokyo.
With minimal preparation, he has fashioned a squad featuring just four players playing regularly for their clubs into an efficient, well-drilled unit which has produced some moments of high quality, whilst also scrambling and battling for every ball.
Bereft of the savoir faire of Daniel Arzani, the muscle and gristle of Harry Souttar - plus the suspended quartet including Riley McGee - Arnold hasn’t been blessed with X-factor options.
But he has pronounced himself “delighted with the desire and commitment of this group”.
“Our willingness to pull together and never take a backward step has impressed me from this group of players,” he added.
“I expect us to go all the way now - we’re not just looking to qualify for Tokyo. We are here to win the U-23 Asian Championship.”
