But there is fight left in the old dog yet and now he hopes to stick around for another year - because he won't be getting a fairytale farewell this season.

The Thunder waved goodbye to their finals hopes in a thrilling nine-run loss to the Renegades in front of 11,319 at Manuka Oval on Wednesday night.

Both sides were jostling for a finals spot alongside the Brisbane Heat - the Thunder needed to win and hope the Renegades drop their final game against Brisbane to sneak into the finals.

The Thunder were facing mission impossible, needing 83 from 42 balls with their finals hopes nothing more than a pipe dream.

When Rohrer took 28 runs off one Jack Wildermuth over in the midst of an 84-run, 38-ball partnership with Arjun Nair, there was life in both Sydney's west and the leafy surrounds of Manuka Oval.

Rohrer (48 from 21) threatened to turn the game on its head in devastating fashion, but soon he followed Arjun Nair (45 from 25) to the change rooms as Kane Richardson (4-22) wrested back the advantage.

The Thunder needed 14 from the final Kieron Pollard over but ultimately fell short, with Rohrer admitting a quick glance at Manuka Oval's picturesque scoreboard brought about his downfall because he momentarily went away from the tonk.

The experienced head laughs while he loved clearing the pickets, he won't be nominating for the Indian Premier League auction.

"Way too old for [IPL], I've got to get back to work on Monday, so that's me," Rohrer said.

"I'm keen to [play BBL], I said that a few weeks ago to the guys here. It's up to them whether they want me. I'm keen to, I'm still loving it.

"I've been hitting well all tournament and probably haven't quite got the opportunity, just the way games pan out sometimes. They know I've been hitting them well as well. It probably hasn't come down to tonight but it helps to put some numbers on the board.

"It's disappointing, in the three years I've been there we've been in a situation where we need to win on the last day to get through. It's probably earlier in the tournament we need to look at rather than a game like [Wednesday].

"There's a few we definitely let get away."

Perhaps it was fate, given the Thunder had hit an early fork in the road when they ran into the BBL's equivalent of a cat with nine lives.

Renegades opening batsman Marcus Harris (64 from 41) emerged from the wilderness to play a starring role and put his side in the box seat to secure a finals berth.

Originally left out of Melbourne's 13-man squad, Harris returned and had just five runs to his name when he received a life when he was dropped by Jay Lenton off the bowling of Gurinder Sandhu (2-37) in the first over.

It was a minor blip on an otherwise sparkling half-century, as Harris carved up the Thunder bowling attack and rubbed salt into the wound when he sent Sandhu into the stands.

Things went from bad to worse for Sandhu when he dropped Harris later on, but it only cost two runs with the Renegades star bowled the next ball.

The run rate slowed as the Thunder fought their way back with a steady flow of wickets, before a horror final over from Mitchell McClenaghan (1-48) saw the score blow out.

McClenaghan conceded 25 runs from his final over, thanks to Beau Webster blasting 18* from four deliveries. It was ultimately the difference in the chase, but Rohrer says that's "just the nature of death bowling".

Melbourne's ominous 6-189 was a score that may have had Thunder captain Shane Watson ruing his decision to bowl first, given he was without his main trump card in Usman Khawaja in the run chase.

While the Thunder's title hopes have been dashed, they proved one thing leading into the finals - no total ever seems safe with the Renegades.