Let’s start by commending the 49ers for signing free-agent wide receiver Anquan Boldin to a two-year contract. Boldin is neither young nor fast, but he’s as tough a wide receiver as you’ll find, and a strong locker-room presence (as those of us who spend only limited time in locker rooms like to say).

Signing Boldin could also allow the Niners to tip over another domino. Now they can trade Michael Crabtree and wind up, instead, with Sammy Watkins.

NFL trades are never as unencumbered as writers like to pretend they are. You have to find a partner who (1) has what you want and (2) believes you are offering fair value in the swap. But they do happen, especially on draft day, and the talent-rich 49ers are in position to make this one happen.

Watkins, for those of you who have stuffed your ears full of clothes-dryer lint to block out Mel Kiper Jr., is an electrifying wide receiver out of Clemson. The NFL draft offers no sure things, but Watkins is as close as they come. He has moves, he has body control, he has hands and he has speed. Not DeSean Jackson, trail-of-scorched-turf type of speed, but enough deep-threat potential to change defensive coverages.

The most recent mock drafts I’ve seen (feel free to add your own cautionary note here) have Watkins going anywhere from No. 4 (to the Jaguars) to No. 9 (the Bills). Honestly, I have a hard time picturing him falling to Buffalo. For the 49ers to get Watkins, they’d probably have to trade up to 3 or 4, or maybe 5 or 6 if they wait to see how Day One plays out.

The teams drafting at 3, 4 and 5 – the Jags, Browns and Raiders – need lots of help at lots of positions. They are not One Player Away from contending. Perhaps one of them could be enticed to trade their top pick for the 49ers’ first-rounder (No. 30) plus Michael Crabtree, plus maybe a mid-round pick.

I’m not here to trash Crabtree. (And if I were, what could I say that Richard Sherman hasn’t printed on a banner and towed through the sky in a small plane?) Crabtree’s hands aren’t as GOAT-y as Jim Harbaugh says they are, but they are indeed very good. He is elusive after the catch and has become more reliable with each season. Colin Kaepernick loves to throw to him in critical situations, for better or worse.

The problem with Crabtree is that his skill set is too similar to Boldin’s. They are possession receivers. When the NFL changes its rulebook to allow an offense to use two footballs on third-and-8, they will be a viable tandem. Until then, they are non-complementary parts. Imagine, on the other hand, a starting threesome of Boldin, Watkins and tight end Vernon Davis. If he had those targets to throw to, Kaepernick might not feel obliged to scramble for yardage every third play in the postseason.

And all those positive qualities I ascribed to Crabtree? They’re the same ones that might get Cleveland or Buffalo to bite on a trade. The 49ers have a terrible recent record of drafting wide receivers, the most recent first-rounders (other than Crabtree) being A.J. Jenkins, Rashaun Woods and J.J. Stokes.

Make a move for Sammy Watkins, and those guys will be all but forgotten. As will Crabtree.