Rohan collided with Blues defender Sam Rowe as they contested a mark in the third term.

Play was held up for several minutes as Swans medical staff attended to Rohan and the motorised stretcher, which was on the ground before play was stopped, then took him from the field.

He was being taken to hospital for assessment, but there were reports from the ground that Rohan was conscious and talking to medical staff.

After the game, Swans coach John Longmire said Rohan was moving okay, but would face precautionary scans.

Before the match, the winless Sydney Swans lost key forward Kurt Tippett.

Tippett suffered an ankle sprain in the round two loss to the Western Bulldogs and returned for last week's clash against Greater Western Sydney. But the Swans spearhead suffered a fresh hip injury late in the club's final training session on Thursday and did not travel to Melbourne on Friday.

Forward James Rose came into the Sydney team in place of Tippett.

Tippett's absence means the Swans made four changes for this clash. Midfielder Kieren Jack succumbed to a hip complaint of his own and will be out for at least two matches.

Carlton has senior players Marc Murphy and Bryce Gibbs available but dropped Dale Thomas to the VFL.

Sydney are on the bottom of the ladder, looking for their first win of the season. Carlton are 17th.

CARLTON 1.3  5.4  10.7  15.7 (97)

SYDNEY 3.2  6.6  8.10  11.12 (78)

The Sydney Swans entered this match with a precarious 0-5 record. This was the personification of a must-win match for last year's grand finalists and a constant of the AFL finals.

For a club that was last in this position all the way back to 1993 – when half of Carlton's team on Saturday wasn't even born – there was an element of entering the unknown when nothing but a victory would suffice to ignite their season.

But no one bothered to tell Carlton about what was at stake for the red and white brigade in this MCG encounter.

The young Blues pulled off a magnificent coup at the 'G, on the back of a dominant second half, to keep the Swans winless and improve their own stocks to two wins and with some handy momentum heading into the middle stages of the season.

On a forgettable day for Sydney, they also had to endure the pain of seeing Gary Rohan fall heavily on his head in a contest with Sam Rowe in the third quarter. The Swan was later up and talking in hospital with a full range of movement and awaiting scans.

Carlton had a range of contributors but special mention must be made of the game of defender Alex Silvagni in his first game for the Blues. The former Fremantle defender won his battle with Lance Franklin, the Sydney forward finishing with just one goal.

Marc Murphy, Bryce Gibbs, the evergreen Kade Simpson, along with Sam Docherty and Sam Rowe, were all excellent contributors

At half-time it was Sydney's six goals to Carlton's five majors. Most were still anticipating the inevitable Sydney surge and an eventual victory over their more inexperienced opponents.

The opposite happened. The Blues were revitalised by the break. Ed Curnow managed a goal after just 30 seconds and Matthew Wright's second goal 90 second later saw them snatch the lead. They weren't to relinquish it again.

A third Carlton goal for the quarter, this one off the boot of Jacob Weitering, had them out to a 10-point lead after seven minutes. Time to throw away the script.

Wright managed his third goal in the confusion when Rohan went down and, upon the restart, the small forward picked up his third goal for the quarter upon the re-start and Carlton had surged to a 23-point lead.

Late majors to Zac Jones and Callum Sinclair calmed Sydney's nerves but the job was still ahead of them in the final stanza.

Carlton kept up their intensity and a trifecta of majors through Patrick Cripps, Matthew Kreuzer and Charlie Curnow sealed the contest and put icing on the cake.

Earlier, the opening of the match before 32,678 fans was very much 16th versus 18th. Both teams were stop-start in their approach and style. Indecision was the order of the day. 

The Swans did eke out their way to an 11-point quarter-time lead, courtesy of three goals to one, but without doing anything of consequence. The Swans of 2016, and of modern history for that matter, hadn't yet materialised in 2017 and now, may not ever do so.

After Simpson snagged the first major of the second quarter, Franklin replied two minutes later with a classic, well, a very classic Buddy moment. Buried deep in the left forward pocket on the 50-metre arc under the MCG scoreboard, he slotted his solitary goal on his left foot off just one step. 

To Carlton's credit, they hung on. Forward Levi Casboult came into the game in a big way and his excellent pack mark and conversion on nine minutes had the Blues grasping at Sydney's feet.

In typical fashion, the Swans put their noses over the ball and the next two goals – through Tom Papley and Isaac Heeney after a questionable free kick – gave them the edge at the main break but not by much.

The sides had combined for 11 goals at the main break and uncertainty hovered over the outcome.

Franklin had been patchy but Carlton were being well served by Docherty (22 possessions), Murphy (19 touches) and Simpson (14 possessions).

That pattern continued and the rest is history. And the Swans are too for 2017. Another finals campaign is an eternity away.

The Swans now host Brisbane Lions at the SCG next Sunday while resurgent Carlton meet old foes Collingwood in an intriguing clash at the MCG next Saturday.