Emmanuel Fernandez, the 23-year-old defender, is being watched by Borussia Dortmund and Bayer Leverkusen. Rangers signed Fernandez from Peterborough in the summer for £3.5 million, and any potential offer from the Bundesliga clubs is anticipated to be significantly higher than that fee. Rangers want to retain their key players. Peterborough is also due to receive a substantial sell-on fee from any future transfer.