Paul Arriola, right, joined D.C. United this summer from Mexican club Tijuana. (By Tony Quinn)

Paul Arriola and Zoltan Stieber, midfielders acquired by D.C. United during a spending spree this summer, are carrying two of the biggest long-term contracts on the team. But according to figures compiled by the MLS Players’ Union, their current salaries are rather modest.

The reason: They arrived in mid-season when salary cap space was limited and the team structured the deals with escalating amounts over the course of their guaranteed pacts.

Arriola, a 22-year-old right wing from the U.S. national team, is listed at $336,000 in base salary and $350,000 in guaranteed annual compensation. However, he is a designated player who will earn more than $1 million in the future, sources said at the time of his transfer from Mexican club Tijuana. Stieber, a Hungarian international who turns 29 next week, is listed at $100,000 in both categories. He, too, will collect considerably more.

They were among five players signed by last-place United before the roster freeze last month. The others were midfielder Russell Canouse ($65,000 base), forward Bruno Miranda ($53,000) and goalkeeper Steve Clark ($72,000). Canouse, who arrived from the German circuit, is also slated to earn much more than is listed. Miranda’s figure is probably lower than he is earning because he’s on loan from Universidad Chile through the 2018 season.

United has been among the thriftiest teams in the league for many years, but with the team struggling and a new stadium opening next summer, ownership opened the purse strings this summer and plans to add at least one additional high-priced player this winter.

A structured deal also affects players such as Atlanta United goalkeeper Brad Guzan, a fixture in the England leagues and with the U.S. national team. He’s listed at only $340,000 base and $400,000 guaranteed.

Here are the base salaries and guaranteed annual compensation for 44 players acquired by MLS teams in recent months (rounded off):

ATLANTA UNITED

Brad Guzan: $340,000 base salary, $400,000 guaranteed comp

CHICAGO FIRE

Richard Sanchez: $65,000, $65,000

Jorge Corrales: $65,000, $65,000

COLORADO RAPIDS

Stefan Aigner: $425,000, $471,000

COLUMBUS CREW

Pedro Santos: $684,000, $731,000

D.C. UNITED

Deshorn Brown: $265,000, $337,000

Russell Canouse: $65,000, $65,000

Bruno Miranda: $53,000, $57,000

Zoltan Stieber: $100,000, $100,000

Paul Arriola: $336,000, $350,000

Steve Clark: $72,000, $72,000

FC DALLAS

Luis Gonzalez: $65,000, $83,000

Eduardo Cortes: $65,000, $65,000

HOUSTON DYNAMO

Tomas Martinez: $315,000, $498,000

Philippe Senderos: $225,000, $243,000

LOS ANGELES GALAXY

Pele van Anholt: $216,000, $216,000

Jonathan dos Santos: $2,000,000, $2,000,000

Michael Ciani: $600,000, $620,000

MINNESOTA UNITED

Sam Nicholson: $235,000, $281,000

Michael Boxall: $225,000, $242,000

Alex Kapp: $53,000, $53,000

Jose Leiton: $53,000, $68,000

MONTREAL IMPACT

Deian Boldor: $324,000, $324,000

Samuel Piette: $90,000, $99,000

NEW ENGLAND REVOLUTION

Krisztian Nemeth: $547,000, $655,000

Gershon Koffie: $120,000, $120,000

Claude Dielna: $780,000, $910,000

NEW YORK CITY FC

Andraz Struna: $76,000, $76,000

NEW YORK RED BULLS

Fidel Escobar: $95,000, $95,000

Muhamed Keita: $200,000, $256,000

Vincent Bezecourt: $53,000, $53,000

ORLANDO CITY

Yoshimer Yotun: $550,000, $600,000

PORTLAND TIMBERS

Larrys Mabiala: $432,000, $481,000

Bill Tuiloma: $53,000, $64,000

REAL SALT LAKE

Jefferson Savarino: $353,000, $376,000

Marcelo Silva: $675,000, $712,000

SAN JOSE EARTHQUAKES

Valeri Qazaishvili: $1,325,000, $1,454,000

Francois Affloter: $120,000, $154,000

SEATTLE SOUNDERS

Kelvin Leerdam: $351,000, $486,000

Victor Rodriguez: $1,000,000, $1,087,000

SPORTING KANSAS CITY

Cristian Lobato: $180,000, $180,000

TORONTO FC

Nicolas Hasler: $65,000, $81,000

VANCOUVER WHITECAPS

Bernie Ibini: $135,000, $174,000

Stefan Marinovic: $65,000, $78,000

Aly Ghazal: $87,000, $212,000

Nosa Igiebor: $65,000, $98,000