Andre Holmes signing his RFA tender with the Raiders

While the Oakland Raiders host wide receiver Michael Crabtree on a free-agent visit, the team's depth at the position is officially getting deeper.

According to an NFL source, restricted free agent Andre Holmes -- who led Oakland with 693 receiving yards last season on 47 catches -- is signing his restricted free agency tender. In a bit of a surprise in March, Oakland gave Holmes a low tender. Had any team signed Holmes to an offer sheet, the Raiders had the ability to match but they wouldn't have received any draft competition had he signed elsewhere.

Holmes is expected to be in the top rotation at receiver. He started 13 games last season after Rod Streater was hurt. Oakland also has James Jones and it is expected to use a high draft choice on a receiver in this month's draft. The team is visiting with Crabtree. He would vie for a starting job if he signs. Earlier Monday, receiver Denarius Moore signed with Cincinnati. The Raiders had no plans to re-sign Moore, who had just 12 receptions in 2014.

CSN Bay Area reported Streater and punter Marquette King were signing their restricted free-agent tenders. Typically, tender signings are formalities, but there was some intrigue in Holmes' case because he was expected to get a second-round tender.