KUSA – As the free-agent quarterback dried up well before free agency had a chance to open, the Broncos did receive a couple phone calls Tuesday from teams inquiring about quarterback Trevor Siemian, a source told 9NEWS.

The Broncos’ primary starting quarterback the past two years, Siemian is available for trade after his team reached agreement on a two-year, $36 million contract with Case Keenum.

When free agency officially begins at 2 p.m. Wednesday, the Broncos will remain in the market for a right tackle, and No. 3 cornerback. The team is also awaiting word on the offer they presented to their own starting inside linebacker Todd Davis.

The team has other holes they plan to address in the draft, where they will have 11 picks, including No. 5 overall.

Siemian and Brock Osweiler, another Broncos quarterback who will enter free agency Wednesday, are expendable now that Denver has added Keenum to a quarterback room that will return former first-round quarterback Paxton Lynch and seventh-rounder Chad Kelly.

There is also a chance the Broncos select a quarterback early in the draft.

Broncos general manager John Elway and head coach Vance Joseph will spend the opening of free agency on the road as they attend Baker Mayfield’s Pro Day at Oklahoma on Wednesday and Josh Rosen's UCLA Pro Day on Thursday.

Nine potential free agents had already reached new deals before free agency begins, including Drew Brees, Jimmy Garoppolo, Josh McCown and Ryan Fitzpatrick, who re-signed with their respective current teams.

Others who reached agreements were Kirk Cousins (Minnesota), Sam Bradford (Arizona), Teddy Bridgewater (Jets), Mike Glennon (Cardinals) and Keenum (Broncos).

The top remaining unsigned free agents are Cincinnati’s AJ McCarron and Miami’s Jay Cutler.

Siemian, who is to draw a team-favorable $1.9 million this year, is the top quarterback available for trade.

Buffalo is one team that does not have a viable starting quarterback option on its roster. Atlanta, with former Broncos quarterbacks coach Greg Knapp may also be looking for a backup, as is Miami among others.