After some eyebrow-raising selection decisions, like the ones to leave out Dinesh Chandimal and Niroshan Dickwella, and name Dimuth Karunaratne as captain despite not playing an ODI since 2015, Sri Lanka stumbled badly in their opening match, a ten-wicket hammering by New Zealand. Although they recovered to beat Afghanistan, the batting proved fallible again, collapsing from 144 for 1 to 201 all out; coming in at No. 5, Mathews lasted just two balls.
As well as tweaking the line-up, Farbrace, who led Sri Lanka to the World T20 title in 2014 and was also assistant coach between 2007 and 2009, said the team needed to channel the spirit that had previously made the small island nation such a resilient performer at major tournaments.
"I watched the game in Cardiff last Saturday against New Zealand and the thing that disappointed me the most about that was that it was a very un-Sri Lankan performance, they weren't on the front foot, they weren't taking the game to the opposition," he told ESPNcricinfo.
"I always think of the Sri Lanka team as a team that take the game to the oppositions, that play smart cricket, they're streetfighters, they're wise and they always get the best out of situations. I thought in that game they were a little bit timid, a little bit taking a backward step and I'd just like to see them take the game on. They've got so many exciting talented players in that team, and I'd like to see them take the game on a little bit.
"We realistically know that we're not one of the strongest sides in the competition but that doesn't mean that we can't reach the semi-finals if we get our performances right at times when other people don't quite hit their straps."
Sri Lanka's batting coach Jon Lewis
"I'd like to see Angelo up the order at four, and I think they have got the capability and the skill to win games in this tournament. I don't like hearing people talk about the fact they are going to finish bottom of the table, and they're not a great team. They've got a lot of skill in there and I think it's time to show that and take opposition on.
"Most Sri Lankan supporters I've spoken to say, 'we just want to see the boys play, we want to see them give something.' The way that they lost that first game in Cardiff was disappointing because they are better than that. I'm not being critical, I would just love to see them go and play. It's easy to say, sitting the other side of the boundary, but that's what they're about. That's what inspires people."
Although Sri Lanka had some success in moving Kusal Perera up to open in their second game - his 78 proved vital in setting a competitive total - Farbrace suggested that they might be better served by sticking with Lahiru Thirimanne alongside Karunaratne at the top of the order. This he felt will also put the onus on Mathews, who has so far struggled on his return to the ODI side after being dropping over fitness issues in 2018.
"It doesn't matter who's in the XI, it doesn't matter who's been left behind in Sri Lanka," Farbrace said. "In my view, there's a couple of players who should be here: Dickwella, Chandimal, should definitely be in this team without a shadow of a doubt. But the lads that are here have the chance to do something.
"I would bat Angelo at No. 4. You can keep him away from the new ball down the order, but the best players should face the most amount of balls. So put him at No. 4, I would move Kusal Perera to No. 5-6, give him a floating role - have Dimuth and Thirimanne opening and then move Kusal down. And allow him to play his natural game. If you've got a good, solid start at the top from Thirimanne, who is a fantastic player, Dimuth, who are fantastic players - let them give you a good solid start and then let's use the next 30 overs after that to cash in and score some runs."
Sri Lanka's batting coach, Jon Lewis, speaking before the Pakistan game, suggested that the management had a similar plan in mind, owing to the "strong Test feel" about squad - Karunaratne won his recall after success leading the Test side in South Africa. However, he admitted: "We haven't been perfect at setting the foundation yet."
Lewis was also hopeful that Sri Lanka would confound some of their critics as the tournament went on, possibly even remaining in contention for the knockouts if results went their way. Escaping with a point against a Pakistan side coming off the back of beating England - and who were clearly more eager to get on to the field in Bristol - thanks to the rain could yet constitute a vital slice of luck.
"It's hard to say for sure what you need to do to reach that semi-final," he said. "It's quite likely that the weather will have an impact on some people's games - and if some people are lucky, that might have an impact on how far as you go as a team. We realistically know that we're not one of the strongest sides in the competition but that doesn't mean that we can't reach the semi-finals if we get our performances right at times when other people don't quite hit their straps and maybe the weather comes in
