Conor Doyle (Derby County photo) Conor Doyle (Derby County photo)

D.C. United’s youth movement continued Thursday with the acquisition of Conor Doyle, a 21-year-old American forward loaned to MLS from English club Derby County.

United won a league lottery for Doyle’s rights through the end of the year and holds an option of purchasing his contract by Dec. 1. Terms of a potential permanent transfer have been agreed upon but not disclosed.

In essence, United has the last three months of the regular season to evaluate him and decide whether he has a long-term future in Washington.

Doyle is expected to begin workouts next week and, pending international clearance, gain eligibility in time for the July 27 match against the New England Revolution at RFK Stadium.

“Although he didn’t play as much as he would have liked, he was in a good environment at Derby,” United General Manager Dave Kasper said. “Conor is another quality young talent who has advanced international experience for his age.”

United, mired in its worst season ever, has refurbished the roster in recent weeks with young Americans: Luis Silva, 24, in a trade with Toronto FC; Jared Jeffrey, 23, in a free transfer from German club Mainz; and Collin Martin, 18, a homegrown signing from Bethesda-Chevy Chase High School and Wake Forest University.

Thirteen others are 25 or younger.

Doyle (6 feet 2) and United midfielder Perry Kitchen were teammates on the U.S. under-20 national team at the failed CONCACAF tournament campaign two years ago in Guatemala. Doyle is now in the under-23 player pool.

After graduating from high school in Texas, Doyle committed to Creighton University but signed with Derby instead. Over three seasons, he appeared in 22 matches (seven starts) in the English Championship, one step below the Premier League, and did not score. He played in one FA Cup match last season. Injuries over his career and appendicitis last fall hampered his development with Derby and he spent considerable time with the under-21 squad.

“We’re pleased that Conor will be able to spend some time with D.C. United and get some games under his belt,” Derby Manager Nigel Clough said on the club’s website. “He’s at the stage where he needs to play some regular football to continue to develop as a player and we’ll watch how he does with interest.”

Although United has taken a decidedly young turn, the club remains in search of experience.

“Youth is a big part of our rebuilding but not the only consideration,” Kasper said. “We still need veteran players.”

United (2-13-4) is actively pursuing trades and overseas targets while continuing to observe trialists, Kasper said. The international transfer window closes Aug. 8; the trade and roster deadline is Sept. 13.

United dealt veteran defender Brandon McDonald, 27, to Real Salt Lake on Wednesday and sold defender-midfielder Alain Rochat, 30, to Swiss club Young Boys two weeks ago. McDonald had lost his starting job and wanted to relocate, while Rochat was eager to return home to Switzerland after Vancouver traded him to United in early June.