The 19-year-old has joined the Gers on loan until January and has already trained with his new teammates.
The winger could make his debut for Rangers this afternoon when Caixinha’s side take on Ross County away from home at the Global Energy Stadium in Dingwall, Highland, as reported by The Daily Record.
Rangers manager Caixinha has spoken highly of the 19-year-old winger and told The Scottish Sun: “Aaron Nemane is a very gifted player who can play in both wide areas. He can create space that isn’t existing in that moment.
“He is quick and aggressive, and gives us an option when players like Josh [Windass] aren’t available.”
Pena, who is 27 years of age and operates as a midfielder, joined Rangers from Liga MX side Guadalajara in the transfer window for a fee reported by The Daily Record to be worth £2.2 million.
The Mexico international has made just one substitute appearance for Rangers so far this campaign, and former Rangers striker Boyd has asked why he is not playing regularly.
“I’m sorry, but the Rangers fans have a right to ask what on earth is going on there,” Boyd wrote about Pena in The Scottish Sun. “They’ve got a right to know why Pena has hardly kicked a ball.
“At 27, he should be at the peak of his career and playing every week. But he’s literally nowhere to be seen. I just cannot get my head around it and find it utterly staggering that he’s virtually gone missing.
“It’s just a bizarre situation for a player Rangers brought to the club as one of their big summer signings,” added Boyd. “He is their equivalent of Scott Sinclair at Celtic.
“The Englishman came to Celtic Park on similar money and has ripped it up. He’s proved to be superb value — the complete opposite, so far, of Pena.”
Rangers are seventh in the Scottish Premiership table at the moment with just four points from three matches, eight points behind leaders Aberdeen, who have played a game more.