"We'll see how these injuries go, but I love Sanu," Shanahan told reporters Monday. "He's a hell of a player. So him being out there is always a possibility. We'll look into everything we have, though.
"But I wouldn't rule that out at all. He's available, and he's definitely a guy I really respect, and I think everyone in this league respects. So we'll see how it goes this week."
The 49ers placed Deebo Samuel on injured reserve last week as he continues to recover from a Jones fracture in his left foot. A hamstring injury also kept 2020 first-round pick Brandon Aiyuk out of the team's Week 1 loss to the Arizona Cardinals.
Raheem Mostert finished as the leading receiver in that game, and his 76-yard touchdown reception in the first quarter accounted for more yards than any of his teammates totaled individually.
Especially if Aiyuk's injury proves to be troublesome, San Francisco would benefit from adding a veteran wideout.
Sanu had a disappointing 2019 season, catching 59 passes for 520 yards and two touchdowns. The New England Patriots gave up a second-round pick to acquire him from the Atlanta Falcons last October but released him earlier this month.
Patriots head coach Bill Belichick was unsurprisingly vague when explaining New England's decision to let the 31-year-old go:
"You know, it's just one of those things that just didn't work out. I have a lot of respect for Mo, but ultimately, things just didn't work out. I think he tried very hard. I think we tried hard. I don't think it was anybody's fault or anything like that. It was just one of those situations that just didn't work out as well as I think everyone hoped it would when the transaction was made."
Shanahan worked with Sanu in 2016, one of his two years as the Falcons offensive coordinator. Sanu finished that season with 59 receptions for 653 yards and four touchdowns in 2016.
Perhaps their time together would help Sanu rebound in 2020 were he to sign with the 49ers.