"The common denominator: They all can fly and would be upgrades at returner for SF," wrote Barrows.
Both Grant and Raymond are scheduled to become unrestricted free agents on Wednesday.
Grant spent last season with the Miami Dolphins and Chicago Bears. The Dolphins made him a sixth-round pick out of Texas Tech in 2016.
Grant had 848 return yards and a touchdown on special teams between the Dolphins and Bears last season, resulting in a Pro Bowl selection.
Raymond spent last season with the Detroit Lions. The Denver Broncos signed him as an undrafted free agent out of Holy Cross in 2016. He spent time with the New York Jets, New York Giants, and Tennessee Titans between his stints with the Broncos and Lions.
Raymond recorded 236 yards on 21 punt returns last season.