Coventry City signed the 23-year-old in January from Swiss side FC Zürich on a four-and-a-half-year deal reported to be worth around £4.4m, but he struggled to make an impression at the CBS Arena, making just five appearances during the second half of the Sky Blues' Championship title-winning campaign without ever starting a game, totalling only 51 minutes on the pitch.
His exit brings Coventry a fee understood to match what they paid for him in January, meaning the club will not lose money on the deal despite his lack of impact on the pitch.
The move also represents a blow for Rangers, who had held direct talks with Coventry over a possible loan for the Surinamese winger and were said to be keen to add his pace and directness to Derek McInnes's options out wide.
Shabab Al-Ahli moved decisively to beat the Scottish club to his signature, with the Dubai outfit planning to register Markelo under the UAE Pro League's "resident player" category, a status that would allow him to apply for a UAE passport after five years and potentially represent the country's national team, having previously been called up by Suriname for World Cup qualifiers without making a competitive appearance for them.
Rangers are now expected to turn their attention to alternative targets, with PSV forward Couhaib Driouech among the names gaining momentum in Glasgow as a result.
Born in Amsterdam and a product of Ajax's academy, Markelo made his senior breakthrough with Go Ahead Eagles before spells at Kustošija and Celje preceded a move to FC Zürich, where he scored four goals in 26 league appearances in his debut Swiss Super League season, form that persuaded the Swiss club to extend his contract to 2030 just months before Coventry moved for him.
Coventry's swift decision to cash in reflects a squad in which the winger simply never found a route into Frank Lampard's plans following the club's promotion push, with the Sky Blues content to recoup their investment rather than persist with a player who had fallen down the pecking order.