Rochina is back at Ewood Park after spending the second half of last season on loan at Real Zaragoza.
Zaragoza suffered relegation from La Liga last season meaning they were unable to try and make Rochina's move permanent.
Rochina, who joined Blackburn in 2011 from Barcelona, found himself out of favour at Ewood Park last season.
The 22-year-old is thought to be well down the pecking order at Rovers with DJ Campbell arriving from Queens Park Rangers on a permanent basis this summer and Leon Best recovering from a long lay-off.
Rochina is thought to be open to a move back to Spain, with Elche keen to bolster their attacking options ahead of life back in the top flight next season.
"Ruben is interested in a move back to Spain if he is not going to figure for Blackburn next season and Elche are an attractive option as they are back in La Liga," a source close to the player confirmed.