The injuries on the 49ers offense are starting to pile up.

San Francisco head coach Kyle Shanahan told reporters Monday that star forward Deebo Samuel will miss “a couple” weeks with a calf injury he suffered in Sunday’s loss to the Vikings.

Samuel has made 13 catches for 164 yards this season, plus a rushing touchdown.

The 49ers play at the Rams on Sunday and then host the Patriots in Week 4.

Over the weekend, the 49ers placed running back Christian McCaffrey on the injured list, who is dealing with a stiff calf and Achilles tendonitis.

McCaffrey will miss four games, including one against Minnesota.

“It’s something we’re thinking about right now,” Shanahan told reporters Friday before McCaffrey was officially placed on injured reserve. “(Thursday) was his worst day. It comes and goes, but yesterday was the day he was in the most pain. It’s something we’ll talk about over the next 24 hours.”

Before he was placed on the injured list, McCaffrey brought the long term into his conversation when talking about missing San Francisco’s season opener, a win over the Jets on Monday night.

“My mindset is every week I go in and play,” McCaffrey said last Wednesday. “There’s been weeks where I go all week and I don’t even feel good enough to do the walkthrough, and then I wake up and my body is capable of a lot of cool things. Mentally, I’m always prepared to play, and then I wake up and it was a group decision, a really tough one.

“I hate not playing, but I see it as a chess move and something that you can hopefully benefit from for the rest of the season.”