Kyle Shanahan: 49ers looking at every possibility with Brandon Aiyuk

It seems unlikely that Brandon Aiyuk will play for the 49ers this season, but coach Kyle Shanahan isn't ruling it out.Aiyuk remains with the team, although he's participating in a hold-in by not practicing. He requested a trade, and the 49ers are talking to teams about a deal since they haven't been able to reach agreement with Aiyuk on a long-term deal."In a perfect world, you'd love [for Aiyuk and the 49ers to work out a deal]," Shanahan told KNBR on Thursday night, via 49erswebzone.com. "But there's a lot of sides to it. There's us, what we want. It's [also] what he wants. There's a whole contract and stuff to that. It's the tough business part of this league, and some years it can be harder than others. This is a very difficult one, but it's something you're always holding out hope for."The Steelers and Browns remain in contention for Aiyuk, whose agent has permission to negotiate a contract with other teams. It's complicated with a team needing to work out a deal with the 49ers and a deal with Aiyuk's agent both to facilitate a trade."There's got to be two teams tied to that, and B.A.'s also got to agree on that, too," Shanahan said. "So anytime that takes three things, it's...