D.C. United signs U.S. midfielder Paul Arriola from Club Tijuana

Olsen addresses recent acquisitions - Via DC United (1:31)

DC United's Ben Olsen discusses his sides newest acquisitions Zoltan Stieber and Bruno Miranda. (1:31)

D.C. United has completed the signing of U.S. international midfielder Paul Arriola from Club Tijuana, the club announced on Thursday.

The MLS club did not reveal the transfer fee, but acknowledged it was the largest in team history.

Sources told ESPN FC that United will pay in excess of $3 million to Tijuana, and will also pay Arriola an annual salary of more than $1 million per season. The figures were earlier reported by the Washington Post.

United also had to acquire Arriola's MLS rights from the LA Galaxy and agreed to send them $300,000 in general allocation money and $200,000 in targeted allocation money over the next years.

The Galaxy held those rights because Arriola spent time in the club's academy and had offered him a homegrown contract, and he was thus considered a Homegrown Player. He later spurned MLS and the Galaxy in order to sign with Tijuana in 2013.

"We have had an eye on Paul for a while, and his intelligence, pace, technical ability and bright future with the national team make him a perfect fit for this organization as we continue to bolster our roster," United general manager Dave Kasper said in a statement.

"Thanks to the investment from ownership, we're extremely excited to have secured a high-caliber U.S. international for the long term."

In his four years with Xolos, Arriola made 114 league and club appearances, scoring 11 goals.

Arriola, who is currently the only designated player on D.C. United's squad, has seen his stock rise considerably during the calendar year, as he's solidified his spot on the U.S. national team, and was part of the Americans' winning effort at the just-concluded Gold Cup.

All told he has made 11 appearances with the U.S., scoring two goals.

The move is the latest in what is amounting to a roster overhaul for United, though the chances of the Black-and-Red making the playoffs seems remote at this stage, with United sitting in last place in the Eastern Conference, with just 19 points in 23 matches.

However, the team has moved aggressively in recent days, acquiring Hungarian midfielder Zoltan Stieber, Bolivian forward Bruno Miranda, and U.S. youth international Russell Canouse -- while letting Lamar Neagle and and Bobby Boswell leave for practically nothing in exchange.

Canouse, 22, moved from Bundesliga side Hoffenheim on Wednesday and signed a multi-year deal. He captained the U.S. team at the 2015 CONCACAF U-20 Championship and spent last season on loan at Bochum.