The Fiji international missed Ospreys' 33-27 Champions Cup loss in Bordeaux.
Prop Nicky Smith is also available after injury for a match coach Steve Tandy expects to be one to savour.
"The weather dictates a fair bit, you can't be throwing the ball around if it's greasy, but if there's any casual supporters at that game, it won't lack in intensity and physicality," he said.
Ospreys have been involved a series of entertaining matches in Europe, the latest being their narrow defeat by Bordeaux-Begles, a match that produced eight tries.
That was in stark contrast with the Scarlets' try-less 9-6 loss at home to Glasgow on Saturday.
"Our game in Bordeaux was really pleasing to the eye and a huge physical effort," added Tandy.
"But I'm sure there'll be some physicality and intensity in the game (on Boxing Day) and I'm sure it'll be a spectacle either way."
His side start 14 points behind their west Wales rivals in the Pro12 table, with just four wins compared to the Scarlets' eight after a slow start to the season.
"It would go a long way to closing that gap on them, but we've got three games now in the Pro12 where we need to put in positive performances," said Tandy.
"The Scarlets have had a real good start to their season but we've got a bit of momentum in the way we're doing things at the minute."
New Zealand scrum-half Brendon Leonard remains doubtful with a shoulder injury.

The devices are fitted with small mobile sites that include a base station and an antenna.
They could also be used to connect remote parts of the UK where coverage is thin.
EE said it planned to deploy such a network in a UK rural area this year.
The drones can stay airborne for up to an hour at a time and the "helikite" balloons for several weeks as they have a tethered power source.
The drone was designed to give short-term targeted coverage to aid search and rescue situations, EE said.
"Innovation is essential for us to go further than we've ever gone, and deliver a network that's more reliable than ever before," said EE chief executive Marc Allera.
"Rural parts of the UK provide more challenges to mobile coverage than anywhere else, so we have to work harder there - developing these technologies will ultimately help our customers, even in the most hard to reach areas."
It was the first time this had been tried out in the UK, said Kester Mann, analyst at CCS Insight.
"Everyone immediately thinks of disruptive players like Facebook and Google when it come to things like balloon-based networks. The traditional networks need to step up so they don't get left behind," he told the BBC.
Google is developing a network of huge balloons to provide connectivity to rural areas around the world, known as Project Loon.
Last month the tech giant confirmed it had closed its internet drone project, Titan, which was designed to bring the internet to remote rural areas.
Facebook's Project Aquila involves building solar-powered aircraft which will fly for months at a time above remote places, beaming down an internet connection.

Monitor said the probe into the Christie NHS Foundation Trust was over concerns about governance and was not over allegations relating to suspended chief executive Caroline Shaw.
Chairman Lord Bradley announced he was resigning from the trust on Friday.
The Christie Hospital said in a statement: "There will be no further comment or interviews."
Monitor said it was examining whether the trust had breached its licence to provide healthcare services by failing "the principles of good governance".
It said there were concerns the board of the trust had "not adhered to the required corporate governance standards".
John Leech, Liberal Democrat MP for Manchester Withington, described the management situation at the hospital as "a mess" following Lord Bradley's resignation.
Lord Bradley said he would leave the trust as soon as a replacement could be found.
Ms Shaw was suspended in November as part of a disciplinary investigation.
Monitor said it will announce the outcome of its regulatory investigation "in due course".
The Christie in Withington said it is the largest cancer centre in Europe and treats more than 40,000 patients a year.
Ospreys hope to have centre Josh Matavesi available for their Boxing Day derby match with Scarlets.
[NEXT_CONCEPT]
Mobile phone provider EE has demonstrated helium balloons and drones that could provide 4G mobile coverage following damage to existing infrastructure.
[NEXT_CONCEPT]
A cancer treatment hospital in Greater Manchester is being investigated by the health regulator.