By Cameron Flynn The San Francisco 49ers are making a significant roster cut this Tuesday afternoon. The NFC West franchise is releasing veteran back Marlon Mack. Mack, who found brief success as the lead back in Indianapolis during 2018 and 2019, had a brief stint in Houston this season before eventually being cut. “The 49ers have released RB Marlon Mack,” Field Yates tweeted on Tuesday. Marlon Mack eclipsed the 1,000 yard mark back in 2019 as a member of the Colts, logging 247 carries and 8 touchdowns. His career high in touchdowns came the year prior, where he scored 9 and had his most effi…