Alexander, 24, was selected by Washington in the sixth round of the 2019 supplemental draft. He signed a four-year rookie deal worth $2.6 million but was waived by Washington coming out of the preseason and re-signed to their practice squad.
From there, Alexander had a brief stint with the Rams before signing a futures contract with the 49ers last year.
In 2018, Alexander appeared in nine games for Washington and recorded four tackles.
Cole, 24, signed with the Dolphins as an undrafted free agent out of McKendree following the 2020 NFL draft. He was waived coming out of camp and later signed to Miami’s practice squad.
The 49ers signed Cole to their active roster last season and he was active for one game.
As a senior in 2019, Cole caught 43 passes for 939 yards and 12 touchdowns in 11 games. He also added 208 yards and a touchdown on eight punt returns and 625 yards and a touchdown on 23 kickoff returns.