Marquez made just nine league appearances last season as an ankle injury ruled him out for a number of months and he failed to regain his place in the side after returning to full fitness.
After falling out of favour with manager Mauricio Pochettino, Marquez had also made clear his intention not to sign a new contract with Los Pericos and, with his current deal due to expire in 2013, it was widely expected the 26-year-old would leave this summer.
However, the move to Mallorca has come somewhat as a surprise with a host of other clubs, including Valencia, thought to be interested in him.
Tejera, 22, also spent six years at Espanyol as a youngster before being picked up by Chelsea in 2006. Three years later he was loaned to Mallorca for six months and the Spanish side took up their option to make the deal permanent.
The midfielder played 15 times last season as Joaquin Caparros' side narrowly missed out on qualification for the Europa League.