The forward endured a mixed first season with the Championship side.
Marco Matias celebrates scoring one of the goals of the season
The 27-year-old joined the Owls after a stunning season in the Portuguese top flight where his 17 strikes made him the fourth highest scorer in the division, and the highest not playing for one of the league's heavyweights Porto or Benfica.
Sheffield Wednesday manager Carlos Carvalhal
And while it appeared that he may be able to replicate that form for Wednesday, as he scored twice in his first five league games - including a stunning volley following a sublime piece of skill against Leeds that was arguably the goal of the season in the Championship - that form was not to last as he would then score just once in 15 appearances in all competitions, while the likes of Gary Hooper and Fernando Forestieri led the line excellently for Carlos Carvalhal's side.
But Owls hero Llera has insisted that Matias has proved that he has the ability to be a game-changer for his current club.
"Marco is a quality player capable of doing something special. We have seen flashes of what he can do in the Middlesbrough and Leeds games last season," he told the Star.
"Wednesday just have to use his quality in the right way.
"Marco scored nearly 20 goals in the top division in Portugal. It's not lucky when somebody does that.
"He is a good player. People have to be patient with him."
As Llera suggests, Matias certainly has the quality to create moments of magic out of nothing as he proved at Elland Road last season to silence the home fans.
And having watched on as Hull's Mohamed Diame settled the play-off final with a fantastic goal, Wednesday supporters will be hoping that Matias can build his confidence up over the coming months as, if they get back to that stage this season, they may be requiring another moment of brilliance to ensure that they do not suffer heartache once again.