Mateta joined Palace from Mainz under Roy Hodgson but struggled for game time with many Eagles fans seeing very little of him and literally not knowing how good he was.
But his fortunes changed after impressing in the FA Cup against Millwall that gave Vieira and his technical team something they had been looking for, his energy and work rate in training has impressed massively too.
Mateta is now likely to lead the Palace line for a while after proving that he has what it takes to play for the club.
““Dougie [Freedman] always saw something interesting in him, and he showed me in training he is a good risk to gamble on that,” Vieira told South London Press
“I am pleased we made that decision because he gives us something different and has been good to the team.
“The Millwall game gave him the confidence and belief that he can play in the team.
“When we decided as a club to keep him, and he signed his contract, the confidence and belief went to a different level.
“It was there the whole time, but it was just about him getting it out, and the goals he scored and the confidence and belief from his team-mates helped him to get to the next level. He has been really good for us.”
The French striker has signed a four and half deal with the South London side and is one of the numerous examples of good deals at the club recently.
The likes of Marc Guehi, Joachin Andersen and loan signing Conor Gallagher have all been massive hits which will lift the club going into the summer transfer window.