The San Francisco 49ers picked up defensive end Arik Armstead's fifth-year option back in April. It was a bit of a surprise to some, only because it carries a $9.046 million salary in 2019. The option, however, isn't guaranteed. At least, not right now.

Armstead's fate is one of several offseason decisions the 49ers will have to make in the coming months. His salary for next season becomes fully guaranteed in March (or in the case of injury).

Kyle Shanahan was asked about Armstead on Friday. The head coach would not make any promises on the 25-year-old's future with San Francisco but did say he is hopeful the team can retain him.

Armstead has been having a solid year with the 49ers. Like last year's top selection, Solomon Thomas, he is always being scrutinized by fans because of where he was drafted. First-round draft picks are expected to produce quicker results, or else fans will prematurely slap the "bust" label on them.

Armstead's three sacks this season are a career-high, and he has only played 50-or-more snaps in a game three times this year. Each of those was during the first three weeks of the season.

By comparison, DeForest Buckner, who plays (mostly) inside, has only one game this season with fewer than 50 snaps — a Week 9 contest on a short week against the Oakland Raiders when he had 49. Of course, Buckner has handled a heavy workload and been consistently good since the 49ers made him a first-round pick in 2016.

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Shanahan believes Armstead is showing growth and can develop into a player who can rack up larger sack numbers.

"He does have that type of ability, so I think that's what people hope for," Shanahan said. "But, that's not just something that you do. That takes a while, and it takes guys some time playing in this league, playing different positions, to really find their groove. I do see that chance for Arik.

"The main thing I like to look for is, are you getting better or are you getting worse? I've seen someone that we've been here for two years with him, we've moved him in some different positions, and I see a guy who is only getting better. If that continues, I think his expectations of things should naturally take care of itself because he has that ability."

Our own Bret Rumbeck recently pointed out that injuries have plagued Armstead throughout his career. That hasn't been the case this season. As a result, Armstead currently ranks as the 18th best edge defender in the NFL but has also shown versatility along the defensive line.

Shanahan sees Armstead as a good player on his defense and hopes to keep him around.

"There's no doubt that I don't want to lose him and I don't think anyone in this building wants to lose good players," Shanahan said. "Hopefully that'll work out. It's not as simple as just him though. It has to do with how you want to allocate everything.

"But, the one thing I do know is that I've been very happy with how Arik has played this year. I still think he can get a lot better and hopefully it's here with us."