US national team coach Jurgen Klinsmann has called in the group that will begin preparations for this summer's Copa America Centenario.

Klinsmann on Monday called in a batch of European- and Mexican-based players who are done with their club seasons to take part in a "transition camp" in South Florida this week ahead of a friendly at Puerto Rico. In the lead-up to Copa America, the US will play friendly games against Puerto Rico on Sunday (noon ET; FS1, UniMás, UDN), Ecuador on May 25 and Bolivia on May 28.

“We are doing this week in Miami and finishing off the week with a game in Puerto Rico because it’s really important in terms of transitioning our players coming in from Europe and some who are already done in Mexico to keep them in a flow, to keep them in a rhythm,” Klinsmann said in a statement. “One of our lessons from last year’s Gold Cup was because the tournament was pushed into July, we couldn’t transition our European-based players and some of the Mexican players perfectly.

“We added some players coming from the younger side to look at them and to get a roster together, but the main purpose of this camp is to keep the rhythm, keep going and to transition perfectly into the preparation for the Copa America Centenario.”

Of the European-based and Mexican-based players who are not available but could contend for roster spots, defenders Ventura Alvarado, Edgar Castillo, and Omar Gonzalez are still in the Liga MX playoffs; defender Timmy Chandler is in a relegation playoff in Germany; midfielder Christian Pulisic is with Dortmund for the DFB Pokal Final this weekend and goalkeeper Ethan Horvath is still in season in Norway.

MLS-based players selected for the final roster will join the USMNT on May 23, after this weekend's league matches.

Klinsmann must name his final 23-man Copa America roster by May 20.

USMNT ROSTER vs. PUERTO RICO

GOALKEEPERS (3): Brad Guzan (Aston Villa), Tim Howard (Colorado Rapids), Zach Steffen (SC Freiburg)

DEFENDERS (7): John Brooks (Hertha Berlin), Geoff Cameron (Stoke City), Eric Lichaj (Nottingham Forest), Matt Miazga (Chelsea), Michael Orozco (Club Tijuana), Tim Ream (Fulham), DeAndre Yedlin (Sunderland)

MIDFIELDERS (7): Alejandro Bedoya (Nantes FC), Emerson Hyndman (Fulham), Fabian Johnson (Borussia Monchengladbach), Perry Kitchen (Heart of Midlothian), Alfredo Morales (Ingolstadt), Caleb Stanko (SC Freiburg), Danny Williams (Reading)

FORWARDS (5): Paul Arriola (Club Tijuana), Julian Green (Bayern Munich), Fabrice Picault (FC St. Pauli), Amando Moreno (Club Tijuana), Bobby Wood (Hamburg)