The 20-year-old Spaniard is Ian Holloway's fourth summer signing, following the arrivals of Stephen Dobbie, Jerome Thomas and Dwight Gayle.
However, the latter is the only out-and-out striker - a position in which the south Londoners are struggling with numbers.
Glenn Murray netted 31 times for Palace last season but faces a long injury lay-off after sustaining a cruciate knee injury, while Wilfried Zaha has now started life with Manchester United.
Veteran striker Kevin Phillips, who netted the decisive goal in the play-off final against Watford, has yet to officially pen a permanent deal and chairman Parish is well aware they need to strengthen in attack.
"People have got to think we lost Wilfried Zaha and then Glenn Murray to injury, and we didn't concede a goal in the three play-off games," he told the Croydon Advertiser.
"We've obviously lost in an attacking sense and we weren't bad defensively anyway.
"I think it's about getting your priorities first at the top end of the pitch because of being a bit thin there."
The rest of the Palace squad is shaping up nicely and Thursday's acquisition of Campana for an undisclosed fee is arguably the most impressive deal yet.
After a foot injury restricted him to just five appearances for Sevilla last summer, Campana captained Spain at the Under-20 World Cup.
The 20-year-old impressed as his side reached the quarter-finals, which helped the goal-scoring midfielder earn a four-year deal with the Premier League new boys.
"I got the first interest through my agent, who said that Crystal Palace were interested and straight away I said 'yes' because for me it was a dream to play in England, especially in the Premier League," Campana told Palace Player, speaking through an interpreter.
"I hope to help the team stay in the league and then move forward.
"What I like to think are my best qualities are to keep the ball and to have good distribution. I have always been a typical Spanish midfielder and I like to move forward and score goals.
"I scored a lot of goals when I was in the academy at Sevilla. That's what I want, but especially to keep the ball and to organise the team."
For boss Holloway, such is Campana's quality that he believes his recruitment could be key to the club's ambitions of survival.
"I'm absolutely delighted," the Palace manager said. "Everybody knows the way I want to try and play football and how fantastic Spain have been over the past few years, so I'm delighted to get a lad of this quality.
"I think he's a fantastic player, his maturity is unbelievable, and the way he plays the game is the way I believe it should be played. He's going to be a great star of the future and the present.
"We're going to try and do as well as we can in this division and making signings like this is really going to help us."