The Toronto Blue Jays have reportedly been unsuccessful in their attempt to extend Marcus Semien's contract, according to The Athletic's Ken Rosenthal.

Semien is set to become a free agent following the 2021 season after completing a one-year, $18 million contract signed last winter. 

The 30-year-old, who earned his first All-Star selection this year, is having one of the best seasons of his career, hitting .266/.332/.526 with a career-high 34 home runs and 81 RBI in 134 games. 

If Semien enters free agency, he'll join a loaded free-agent shortstop class that includes Trevor Story, Javier Baez, Carlos Correa, Corey Seager and Andrelton Simmons.