The 49ers have received little return on the investment of their 2017 No. 3 overall draft pick.

General manager John Lynch acknowledges defensive lineman Solomon Thomas has not produced to the level expected of a player selected so early in the draft. But Lynch said he has not given up on Thomas, who ranks 17th on the team in tackles and has one sack as a part-time player through 10 games.

“A lot of people use the word ‘bust’ or whatever,” Lynch said on The 49ers Insider Podcast. “He’s not that. He’s a good football player for us.

“I think a lot of people struggle when you have the No. 3 pick. ‘Why isn’t he in there more?’ And that’s something we have to answer. But you have to earn those opportunities. That’s something Kyle (Shanahan) has always been clear on. Solly needs to continue to earn those. And we need to continue to put him in position to thrive.”

Thomas appeared in 14 games with 12 starts as a rookie. With 41 tackles and three sacks, Thomas showed signs he could take his game to a higher level. But Thomas’ production has regressed in his second season.

Thomas, 23, faced tragedy in the offseason when his older sister, Ella, died from suicide on January 23. Thomas has used his platform as an NFL player to bring awareness to mental health issues. It is only reasonable to assume his real-life anguish has impacted his on-field production.

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“It’s been tough on Solomon,” Lynch said. “I can’t even imagine. I often try to put myself in his position, and I know the struggle that he’s going through. Solomon is very aware that the struggle is real, that it’s something he deals with every day.

“But, also, he needs to find a way to come and be the best he can be at his job.”

Thomas has two years remaining on his rookie contract after this season, and Lynch said he expects the former Stanford star to come back from the bye week and make an impact as the 49ers close out the season.

“I’m still a big believer in Solomon Thomas,” Lynch said. “A lot of people say, ‘Why?’ You go back and study the history of defensive linemen in this league. A lot of them don’t figure it out in Year 1. They don’t figure it out in Year 2.”

Lynch added, “In this second half of this Year 2 for him, he’s got to really start being the player we all know he can be. Some of that is opportunity, and putting him in situations where we think he can thrive. And I think we’ll see that in the second half of this year.”