Paul Arriola, right, is among only 16 contracted players for D.C. United. (By Tony Quinn)

After MLS Cup ends Saturday in snowy Toronto, an offseason of trades, loans, transfers, drafts and signings will commence around the league. For D.C. United, it’s going to be a very busy winter.

Before we get to United’s roster, here are the key dates:

Tuesday: MLS expansion draft for incoming Los Angeles FC, which will select five players from around the league. No club will lose more than one player and 17 will not lose anybody. All clubs will protect 11 players (homegrowns are exempt from the draft and do not have to be protected). After retaining only about half of the roster, United is in almost no danger of losing a primary player. It would, however, have to protect departing goalkeeper Bill Hamid, should it want to avoid possibly losing his MLS rights to LAFC.

Tuesday: Free agency begins for out-of-contract players, or those who did not have their options exercised. To qualify for free agency, a player must be at least 28 years old with eight years’ experience in MLS. Sean Franklin and Patrick Nyarko are eligible after United declined their contract options. Last year, nine league free agents signed with new clubs.

Wednesday: Wavier draft for players who are not eligible for free agency or the re-entry drafts. Few, if any, will be selected.

Dec. 15: First stage of re-entry draft. Los Angeles Galaxy picks first, D.C. goes second and so on, based on the 2017 reverse order of finish. Clubs must exercise the previously declined option or extend a bonafide offer. Last year, three players were selected.

Dec. 21: Second stage of re-entry draft. Los Angeles Galaxy picks first, D.C. goes second and so on. Clubs are required to make a genuine offer to the player within seven days. Last year, four players were selected.

Jan. 11-17: MLS scouting combine in Orlando for draft-eligible college players.

Jan. 19: MLS college draft in Philadelphia. Los Angeles FC picks first, followed by the Galaxy and D.C.

Jan. 22: MLS training camps open.

Feb. 20-22: First leg of CONCACAF Champions League’s round of 16 for Seattle Sounders, Toronto FC, New York Red Bulls, FC Dallas and Colorado Rapids. (The draw is Dec. 18.)

Feb. 27-March 1: Second leg of CONCACAF Champions League’s round of 16.

March 2-4: MLS regular season openers.

As for United’s roster, only 16 players are under contract, leaving up to 14 available spots. Some players with rejected contract options could resurface at training camp. “Lot of moving parts on all fronts,” one club official said.

With the senior-roster departures of Hamid, Franklin, Nyarko, Bobby Boswell (traded in August), Chris Rolfe (retired), Marcelo Sarvas, Lloyd Sam and Deshorn Brown, United cleared a large chunk of space under the salary cap. However, full-season contracts of players acquired this past midseason will occupy a block of the 2018 capacity.

It’s unclear how much allocation money and targeted allocation money the club has stockpiled. United is keen to sign a third designated player; Paul Arriola and Luciano Acosta are classified as DPs in 2018.

University of Maryland junior attacker Eryk Williamson (U.S. under-20 national team) is on the homegrown radar.

Goalkeeper: With out-of-contract Hamid heading to Danish club Midtjylland, Steve Clark ascends to the No. 1 slot — for the moment, at least. United plans to sign another experienced keeper to compete for the starting job. Travis Worra will fill the No. 3 role. United wasn’t comfortable with the option terms in Clark’s contract, so the sides renegotiated. A deal was reached this week.

Center backs: Captain Steve Birnbaum and Kofi Opare are the incumbents, with Jalen Robinson in the mix, but the club is planning to pursue another proven central figure to compete for a starting job.

Outside backs: There’s a scarcity of options after the contracts of Franklin, Chris Korb and Chris Odoi-Atsem were dumped. Taylor Kemp is a three-year starter on the left corner and Nick DeLeon is the lone candidate on the right. Odoi-Atsem, a 2017 first-round draft pick who plays on the right, was invited to training camp and, if he accepts, would attempt to earn a new pact.

Central midfielders: There is some depth here with Russell Canouse, Jared Jeffrey and Chris Durkin (who turns 18 in February) as the deep-lying options and Luciano Acosta and Ian Harkes as attackers. Nonetheless, the club seems likely to add another piece in the middle of the park.

Wide midfielders: Two summer arrivals are the incumbents on the wings as Paul Arriola (U.S. national team) mans the right side and Zoltan Stieber (Hungary) takes the left. That’s it, though, unless DeLeon returns to midfield. Expect multiple signings.

Forwards: The cupboard is almost bare. Patrick Mullins needs to return to form after a forgettable season (aside from that four-goal performance late in the year) and Bruno Miranda (who turns 20 in February) enters his first full campaign on loan from Universidad de Chile. Among many missions this winter, United’s top priority is to sign a proven goal scorer. This season, the club finished tied with Colorado for the fewest goals in the league (31) and equaled its own record for scoreless performances (17 in 34 matches).

Training camp outlook: United is in the process of finalizing preseason plans in Clearwater, Fla. A set of Florida friendlies is in the works, but only one has been finalized so far: Swedish club Malmo on Feb. 8 at a location to be determined. United has also announced a Feb. 24 away match against second-tier Las Vegas Lights, a USL expansion team.