Wanting improved fitness to break into the top-10, Bernard Tomic has blamed a heavy off-season training block and a “terrible” serve for a deflating first round exit at the Brisbane International.

Tomic’s Australian Open preparations started dismally at Pat Rafter Arena where he lasted just 83 minutes against eighth-seeded Spaniard David Ferrer, falling 6-3 7-5 in a hail of unforced errors.

Traditionally the Gold Coaster performs well at his home tournament, but he struggled badly on serve – dishing up eight double faults – and couldn’t find his range with his forehand.

Ferrer, the former world No.3 who turns 35 next month, was far more consistent and composed to win through to a second-round clash with Aussie wildcard Jordan Thompson.

The 2013 French Open finalist even asked Tomic as they shook hands at the net if he was sick, such was the lack of energy the world No.26 displayed in some points.

But Tomic, broken in his first two service games, said he just “felt flat” and overcooked due to undertaking a new, enhanced pre-season training block since last playing in October.

“I felt like there is a huge possibility that doing a lot of fitness and that time away from tennis had a lot to do with this match today,” he admitted.

“I’m never going to be the fittest guy on tour. I’m 6’5” (195cm), so it’s not easy for me to be like Ferrer or (Andy) Murray or these players that are very low centre of gravity.

“I have to do something different. I have to rely on different things, obviously my serve, which let me down today.

“I feel like, like I said, I’m not going to be the fittest guy on tour, but I can improve so much more.”

Tomic noted he boasted the fourth best first serve percentage on the ATP tour last year (behind Rafael Nadal, John Isner and Nick Kyrgios) but his first 2017 display was in stark contrast.

“I think that’s what cost me – I served terrible,” he said.

Ferrer, who admits his days in the top-10 are behind him, felt Tomic just failed to keep his focus in the key moments as well as the Spanish veteran.

“He has everything to be a top-10 (player),” said the world No.21, who lost their previous two encounters.

Tomic, now to play exhibition matches in Sydney and Melbourne, denied it was a dent to his confidence heading towards the Australian Open where he made the fourth round last year.

French world No.39 Nicolas Mahut also won through to the second round after overcoming compatriot Stephane Robert 4-6 6-3 6-4.