Having held on to their Toronto Centre stronghold in last Thursday's by-election, Ontario Liberal MPPs were presumably able to make it through last night's Super Bowl party without gang-tackling Premier Dalton McGuinty.

That may yet prove their inclination, though, if Mr. McGuinty immediately hands a plum job to the newest addition to their caucus.

It's a foregone conclusion around Queen's Park that Glen Murray, a former Winnipeg mayor who moved to Ontario six years ago, will wind up in cabinet sooner or later. He himself was less than subtle in hinting at that fate while he was campaigning for George Smitherman's old seat, although he publicly denies any deal was in place with Mr. McGuinty.

The question is how long Mr. Murray will have to bide his time.

The rumour last week, before the votes in Toronto Centre had even been counted, was that Mr. Murray wouldn't have to wait very long at all. Sources suggested that Infrastructure - a previously separate ministry that was paired with Energy in 2007 to create a new mini-empire for Mr. Smitherman - would quickly be split off again and handed to Mr. Murray.

That would make some sense, since the combined ministry proved burdensome even for the hyperkinetic Mr. Smitherman. It seems an awful lot to ask of his relatively inexperienced replacement, Brad Duguid - and it will be all the more so if Mr. Duguid loses his experienced deputy minister, Saad Rafi, rumoured to move soon to the Health Ministry.

It's also possible that Mr. Murray will be asked to take over Aboriginal Affairs, a ministry that's been lumped in with Attorney-General Chris Bentley's responsibilities. Since last month's cabinet shuffle, there's been speculation that Mr. Bentley is just keeping that seat warm until either Mr. Murray or Bob Chiarelli - another former mayor running in another by-election in Ottawa - is ready to take it.

It's not hard to understand why Mr. McGuinty would want to move quickly. He's well into the second half of his mandate, he's struggling to project a sense of urgency, and his cabinet could use both an injection of personality and a stronger Toronto presence.

But there's a reason, too, why some senior Liberals are counselling Mr. McGuinty to send Mr. Murray to the backbenches for a few months.

As is the case with many second-term governments, Mr. McGuinty's caucus has been getting restless. There are the familiar complaints of power being too centralized, good people being under-utilized, and the Premier having lost touch with the public.

A small number of Liberal MPPs have grown brazen enough to air their grievances with the media, albeit mostly anonymously - a phenomenon that's been particularly problematic for the Liberals in trying to present a united front on their controversial harmonized sales tax. There's also all sorts of caucus grumbling about the province's multibillion-dollar green-energy deal with the Samsung Group, which Mr. McGuinty hoped to present as a straight good-news story.

Mr. McGuinty wouldn't be much of a leader if he allowed himself to be held hostage by his most disgruntled MPPs. But neither is it necessarily a good idea, after a pretty brutal 2009, to start 2010 by slapping them in the face - which is how instantaneously promoting a newcomer would be interpreted by Liberals already miffed at being overlooked in January's shuffle.

Mr. Murray's personality would not help matters. Bright and bursting with ideas, particularly on municipal matters, he's accumulated a good number of admirers in his adopted city. But prone to being the loudest voice in the room, and not being especially adept at hiding his ego, he also rubs some people the wrong way.

It remains to be seen how Mr. Murray, having run a city, but never served in a trational party's caucus, will fare as a team player. In a cabinet of mostly mild personalities, he's certainly going to stand out. But he might stand out a little less if he knows what the legislature looks like from its backbenches, not just the front ones.

As the Liberals' caucus retreat begins in earnest today, Mr. McGuinty will undoubtedly hold up Mr. Murray's comfortable victory as proof the Liberal brand remains strong.

But the mood won't be entirely buoyant. And it could be considerably less so the next time the Liberals convene, if the Premier doesn't wait to capitalize on the by-election's returns.