San Francisco 49ers: 2016 Starters whose futures depend on 2017

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Sep 12, 2016; Santa Clara, CA, USA; San Francisco 49ers tight end Vance McDonald (89) scores a touchdown against the Los Angeles Rams in the fourth quarter at Levi’s Stadium. The 49ers won 28-0. Mandatory Credit: John Hefti-USA TODAY Sports /

Vance McDonald

It was clear that Vance McDonald’s 49ers future was on the line the second it emerged San Francisco had looked into trading away the tight end. McDonald signed an extension until 2022 prior to John Lynch and Kyle Shanahan’s arrival, yet his long-term status with the team remains far from secure.

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After two seasons of substantial struggle, McDonald has improved as a pass-catcher, with his athleticism making him a downfield threat, while his size has seen him develop into the 49ers’ primary redzone threat.

McDonald averaged 16.3 yards per reception in 2017, but with the 49ers signing a blocking tight end in Logan Paulsen and adding two rookies in George Kittle and Cole Hikutini, he figures to have plenty of competition and cannot afford to have a let-down year.

Drops have been McDonald’s primary issue throughout his pro career and, if he is unable to showcase safe hands in 2017, a trade to another team will become much more feasible.

October 2, 2016; Santa Clara, CA, USA; San Francisco 49ers offensive lineman Trent Brown (77) blocks Dallas Cowboys defensive tackle Tyrone Crawford (98) during the first quarter at Levi’s Stadium. The Cowboys defeated the 49ers 24-17. Mandatory Credit: Kyle Terada-USA TODAY Sports /

Trent Brown

The 49ers could not have expected to get as much out of Trent Brown as they have when they drafted him in the seventh round in 2015. After a rookie season in which he flashed significant potential, Brown started 16 games in 2016, but faces competition for his right tackle spot in 2017 after the 49ers brought across Gary Gilliam from the Seahawks.

With a wide base and relatively quick feet, Brown — who comes in at a massive 6-8 and 355 pounds — has consistently impressed in pass protection. But Brown has had a great deal of difficulty as a run-blocker, missing assignments and often struggling to get to the second level.

Athleticism is key for any lineman hoping to succeed in the zone-blocking system, and Brown has shown very little of it. Gilliam is unlikely to be able to displace Brown as the starting right tackle. However, should Brown struggle in Shanahan’s system, the 49ers could soon be looking for his replacement.