Portuguese boss Matos made his claims after the Swans had drawn 2-2 at home to promotion-chasing Middlesbrough - the home side's third successive match without a win.
Matos' frustration appears not with supporters inside the stadium, but with the tone of online criticism aimed at Wales international Cullen.
It’s a stance that echoes the view previously expressed by Wales boss Craig Bellamy, who has also questioned why Cullen attracts so much stick.
Cullen again played a demanding, selfless role in Swansea’s Bank Holiday Monday draw draw and Matos was quick to highlight his importance after the game.
“We need to take care of these players because they are the heart and soul of the club,” said Matos.
“All of them. Not only Liam. All of them.
“Get rid of all the expectations, understand that the history of the club is something to enjoy, but not something you need to carry on your back all the time.
“I really don't know how everyone feels so much in doubt when it's Liam or something similar.
“But when we speak about Liam, today he played two separate positions in a hard role that was defensively needed to support Sam Parker, who was making his first start of the season.
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“The way he pressed allowed us less one v ones that side, overloading the centre, of course.
“Then I needed to move him because of the way our players were getting tired and the positions we needed to get fresh. He understood what we had to do.
“I think all these players deserve a lot. Liam is one of them. We as a club, we need to take care of our own.”
Matos stressed that emotion from supporters is natural, but believes it must be channelled more constructively.
“I think fans are emotional. But we need it to be emotional at the right time, especially in these kinds of situations.
“That's the culture we want. That's the culture we need to go for the future.”
On the pitch, Swansea showed resilience to claim a point in a match shaped by three penalties.
Zan Vipotnik struck twice from the spot after Alex Bangura’s early opener for Middlesbrough, before Tommy Conway equalised late on with a third penalty of the afternoon.
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Cullen himself nearly had the final say, forcing a late save from Sol Brynn, capping a performance that underlined the very qualities Matos was so keen to defend.
The result leaves Swansea 15th and without a win in three matches, but Matos was satisfied with the discipline and structure his side showed against strong opposition.
“We needed to control the game without the ball, getting compact, getting the right timings, the right positions, the right organisation.
"We knew Middlesbrough is a really good team with the ball, with a lot of individual technique in all positions, which can hurt you.
"With two games [over Easter] and all the internationals arriving last Thursday, you need first to be organised and compact and then you can put pressure and be effective.
"That's what we tried and then when we had the ball we tried to use it to create some good chances. We needed to use counter-attacks and for that some players were really important. I think overall it was a good game."
Middlesbrough boss Kim Hellberg accepts his side are now likely facing a must-win run-in of five matches if they are to keep their automatic promotion hopes alive.
A fifth straight game without victory has left Boro trailing in the race for the Championship top two.
With Ipswich Town climbing above his team on goal difference - despite having played two games fewer - Boro boss Hellberg did not shy away from the scale of the task ahead.
“Ipswich are in a massive pole position,” said a rueful Hellberg.
“We have to find wins and points. Even though this period has been poor, we have suffered only a few defeats. It’s the draws that have killed us.
“We probably have to win all five of our remaining games to get past them, to be fair.
“It’s very difficult to get those wins, but we will try and get as many points as possible and then we will see where we end up.”
Boro at least avoided defeat thanks to Tommy Conway’s 75th-minute penalty in a contest dominated by three successful spot-kicks.
They had started brightly, taking the lead through a superb strike from Alex Bangura, but their grip on the game slipped before half-time as two rash challenges handed Swansea the initiative.
Zan Vipotnik, the Championship’s leading scorer, punished both errors from the spot, cancelling out Bangura’s opener and then putting the hosts ahead in stoppage time after Sol Brynn brought down Jisung Eom.
Conway eventually restored parity after another contentious penalty decision, but the result still felt like two points dropped for a side whose promotion push has lost momentum.
With just two wins in their last 10 outings, Boro’s inconsistency is proving costly—especially after Millwall’s home defeat to Norwich opened the door to climb the table.
Bangura’s earlier mistake, a clumsy challenge on Liam Cullen, set the tone, while Brynn’s needless foul on Eom compounded the damage before the interval.
Hellberg admitted: “You cannot concede penalties like that.
“I know that, the players know that. But everyone makes mistakes - I do it every day.
“It’s how you recover that matters. It’s easy to blame people but I thought we were strong and I was impressed with the group.”
Middlesbrough responded with greater intent after the break, and Lawrence Vigouroux had to be at his best to keep out Aidan Morris’s curling effort from distance.
But Swansea’s advantage was wiped out when referee Matthew Donohue awarded a third, highly debatable penalty after Eom went down under pressure from Callum Brittain.
Conway stepped up and drilled his effort straight down the middle to make it 2-2.
