A powerful sweep from Jake Doran hit Mendis during the middle session of the day-night match and having been in considerable pain, he quickly left the field for treatment. He spent the rest of the day icing the injury to his right ring finger, but has now been shown to have sustained no breaks or fractures.
"We took him for an X-ray in the morning and it showed that he was fine," team manager Jeryl Woutersz said on Friday. "We're not sure if he will bat yet, because the finger is quite sore. But he's okay."
The news will be a relief to Sri Lanka, for whom Mendis is a vital top-order batsman, especially in the absence of Angelo Mathews. Mendis comes into the series on the back of impressive form against New Zealand where he made an unbeaten 141 in the first Test and 67 in the second. Last year, he was the second-highest scorer in Tests with 1023 runs at 46.50.
The team is still waiting for confirmation on the extent of the injury to fast bowler Nuwan Pradeep, however. Pradeep had left the field after two overs on Thursday, with a suspected hamstring strain. Woutersz said Pradeep would undergo a scan sometime on Friday before the team made any further decisions on his further participation in the tour. Pradeep has had severe problems with injuries - and especially his hamstrings - over the years.
Overall, Sri Lanka had had a mixed first day in the field in Hobart, reducing the CA XI to 5 for 98 before an unbroken stand of 218 between Kurtis Patterson and Doran became the dominant feature. Keeping the four players in Australia's Test squad to 40 runs between them was a major plus, but head coach Chandika Hathurusingha was far less impressed with a familiar problem rearing its head in the shape of 12 no-balls - eight delivered by Kasun Rajitha.
"It's a big concern," he said. "We need to get that right because it's happened to us again. The spinners also bowled no-balls in the England series and we got wickets off no-balls. We need to get it right soon.
"It's about being aware of the line right in front of you basically. I think they are trying a bit too hard when the ball gets softer to get the ball through. It's a mental thing so they need to adjust knowing they have to stay back."
The softness of the ball Hathurusingha referred to was part of a larger concern he had about the durability of the pink ball as the day wore on, but he hoped the Gabba pitch and outfield may aid its longevity during the first Test, starting January 24. Sri Lanka couldn't keep hold of the run-rate later in the day either, with their spinners conceding more than five an over.
"We got a lot of information about the pink ball as well because we are playing with it after a long time. The last time was in Barbados with a Dukes ball and this ball is different, it got softer very quickly. I thought our guys bowled really well at the start then we need to find how to be in the game when it gets softer."
*12.40pm, January 18: This story was updated with news of Mendis' x-ray results and the latest on Nuwan Pradeep