The San Francisco 49ers on Thursday finalized a one-year agreement with veteran wide receiver Marquez Valdes-Scantling and placed the 30-year-old on their 16-man practice squad rather than the 53-player active roster. General Manager John Lynch said the club was “thrilled” to add the deep-threat option, who owns 205 career catches for 3,566 yards and 20 touchdowns across stints with Green Bay, Kansas City, Buffalo and New Orleans. Valdes-Scantling was released by Seattle two days earlier after training camp and cleared waivers before joining San Francisco. His arrival is intended to shore up a receiver unit that has been thinned by injuries ahead of the Sept. 7 opener against the Seahawks. The 49ers also re-signed wideout Russell Gage Jr. to a one-year deal and released safety Richie Grant to clear roster space. In related transactions, the club filled out its practice squad with quarterback Adrian Martinez and running back Sincere McCormick, bringing both the 53-man roster and practice squad to capacity.