The All-Australian hobbled off Mission Whitten Oval in distress during Friday night's seven-point loss after her right foot was trod on by an opponent.
"Ally will have a scan on Saturday," Swans coach Scott Gowans said.
"It's the same foot ... she got trod on.
"It's hard to tell on assessment whether it's actually something to do with the injuries she's had, or whether it's just because someone stood on her foot.
"The potential is if it's just been trod on, it's 'move on'.
"We're going to be really ultra-careful."
Sydney were mown down in Morphett's absence, the Bulldogs overcoming slender half-time and three-quarter-time deficits to finish strongly and notch their second successive win, 5.9 (39) to 5.2 (32).
"It's a pretty nice feeling - it's our first win at Whitten Oval in over 900 days," Bulldogs coach Tam Hyett said.
"We knew if we were structurally sound across all three lines, that would give us a good opportunity to have some time in the forward half."
The ball lived inside the Bulldogs' attacking 50 down the stretch as Britney Gutknecht's first goal of the season midway through the fourth term - the only goal of the quarter - put the hosts in front for good.
The Dogs started strongly, highlighted by smart-snapped goals to Sarah Hartwig and skipper Deanna Berry, but their bench was shortened at the 13-minute mark when ruck Jorja Borg injured her left knee.
"It doesn't look good at this stage," Hyett said.
"She'll go in for scans Saturday morning - but not great."
As a result, Alice Edmond rucked solo against Morphett, and the athletic 189cm Bulldog acquitted herself superbly, combining neatly with onballer Jess Fitzgerald.
Sydney, spearheaded by Laura Gardiner (31 disposals), regularly looked more slick on the outside and more clinical in attack but they became beset by poor decision-making and execution errors late.
The Swans started the second stanza by streaming out of the centre-square with three goals in the first six minutes before Ellie Bennetts got one back for the Dogs after converting a 50m penalty.
The lead changed hands throughout an engrossing third-term arm wrestle before Morphett's exit and a sharp decline in the Swans' skill level paved the path for a strong final flourish from the Bulldogs, who won the fourth-quarter inside-50 count 12-2.
"We just made some silly decisions," Gowans said.
"We'd get the ball in our front half and turn the ball over.
"When the Bulldogs got that momentum, we didn't have the footy IQ across the field to make decisions to possess the ball and take our time.
"We always wanted to go quick, which was a problem for us."
