Having survived the toughest challenge of his career, courageous paceman Ryan Harris is now caught between conflicting desires in racing the clock to win back his Test place.

Harris has one, possibly two, Sheffield Shield games for Queensland to regain new-ball duties for Australia’s four-Test series against India, starting December 4 at the Gabba.

Told by national selector Trevor Hohns not to put too much pressure on himself, the 35-year-old also knows he must hit top pace and form to warrant an immediate recall.

Although Australia were wiped 2-0 by Pakistan in the UAE, Harris denied he could walk back into Michael Clarke’s attack by merely proving his fitness following his mentally taxing six-month rehabilitation from knee surgery.

He plainly admits he’s not up to scratch after two club cricket outings and 27 overs (for a match return of 3-91) in the Futures League, where his angst and knee soreness was evident from the boundary fence.

“I wasn’t happy with the way I bowled last week, that’s natural,” the bustling quick said on Thursday. “I always have those dummy spits when I come back from injury.

“The more I bowl the better I get, it just takes time.”

Harris not only wants better consistency, hitting his line and length regularly, but to also push past 140kmh as coach Darren Lehmann demands.

“Boof (Lehmann) wants us bowling good pace so if I’m bowling 130kmh-125 kmh not going to pick me for that reason,” he said. “If I’m not bowling up to scratch I’m not going to be there.

“I want to be able to make sure I can get back to the form that I had last year and in previous years.”

But here’s the rub. Harris needs more time at the bowling crease but Australia’s selectors also want to take a cautious approach to their ageing swing and seam asset.

The world No.2-ranked bowler isn’t sure himself if he has enough time, starting with the Shield clash with NSW at the Gabba on Sunday, and then possibly another against Tasmania.

“Maybe I’ll need both of them,” he said. “Who knows?

“The thing for me is I’ve had five-and-a-half months out and if I try to get back to the way I was last bowling in two bowls it’s just not possible.”

It’s been eight months since Harris bowled Australia to a series-clinching victory over South Africa in Cape Town on his dodgy right knee, that had undergone a handful of previous operations.

Harris said his rehabilitation was beset with fears he may have been too old to return to the form and fitness required to add to his 24 Tests and 103 wickets, at 22.54.

“I must admit it’s been tough getting back,” he said. “It’s been harder this time.

“It’s the hardest rehab I’ve had to go through mentally and physically, questioning whether I can do it.

“The bottom line is I still want to play and I still think I’ve got something to give.

“I’ve still got unfinished business there especially with the Ashes (defence next year) and I want to make sure I can get there.”