One of the biggest surprises in the NFL on the first day of free agency was the 49ers signing running back Jerick McKinnon to a four-year, $30 million deal, making him one of the highest-paid players at his position. Looking at his career stats, it would appear to be a strange move by San Francisco, given that McKinnon has fewer than 2,000 rushing yards throughout his four years in the league. However, it’s his skill set as a receiver out of the backfield that Coach Kyle Shanahan covets.

McKinnon is a small, shifty back who runs good routes and has reliable hands. In Minnesota, the Vikings mostly used him on screens and checkdowns, but occasionally they would find a way to get him more involved in the passing game.

Here, the Vikings run the mesh concept, which consists of two underneath crossing routes and a receiver spotting up in between them as an option against zone. The mesh concept also works well as a way to pull defenders in toward the middle of the field while the running back works outside on a wheel route.

The Bengals defenders are naturally drawn into the middle of the field, as that’s where all the routes are meeting. It creates plenty of space for McKinnon to run his wheel route, giving the quarterback an easy throw for a big gain. McKinnon shows off his ability to pick up yards after the catch, cutting inside toward the safety and making a sharp cut that nearly beats him.

The Vikings would also occasionally motion McKinnon out wide.

This time, McKinnon motions outside of the tight end to the right of the formation. McKinnon initially runs underneath the tight end before pivoting back outside.

The Rams linebacker reads the route as a play designed to create traffic for him, so he works around the tight end and overcommits inside. McKinnon puts on the brakes and sharply cuts back outside, creating plenty of separation from the linebacker. McKinnon makes the catch and bursts up the sideline for a first down before the safety forces him out of bounds.

Expect to see more of these types of plays for McKinnon in San Francisco. When Shanahan was the offensive coordinator with the Falcons in 2016, he used running back Tevin Coleman similarly as a key cog in the best offense in the NFL that season.

Shanahan liked to line up Coleman in the backfield initially before motioning him outside or to the slot, as he does here. This was an easy way to get a good athlete matched up on a slower linebacker. Shanahan would then run simple route combinations to help Coleman get open.

The tight end releases up the seam toward the linebacker covering Coleman. His objective is to create traffic for the linebacker so Coleman can break free inside by running underneath. That’s exactly what happens, as Coleman runs wide open across the middle, making the catch and then creating extra yards afterward.

If Shanahan found a linebacker he thought he could exploit in coverage, as he did against the Broncos in 2016, he would continue to motion the running back out of the backfield to take advantage of it.

Like before, Shanahan motions Coleman to the slot, where a linebacker follows him. The Falcons run a slot fade concept, with the outside receiver running a hitch to occupy the outside corner underneath.

The play is designed to isolate a linebacker in coverage on a better athlete in Coleman. It works to perfection, as Coleman simply runs past the linebacker and down the sideline for a big gain.

Shanahan will also involve running backs in route combinations from the backfield.

Against the Seahawks, Shanahan and the Falcons run a scissors concept, which asks two receivers, typically a wide receiver and a tight end, to cross over their routes down the field, resembling a pair of scissors. This is a great concept to run against a team that plays cover-three as often as the Seahawks do. However, nearly everyone attempts to run scissors against the Seahawks, and they understand out to defend it. So Shanahan adds a twist, having Coleman work as part of the scissors concept while the tight end works to the flat.

The play works exactly how it’s designed to. The outside receiver drags the cornerback inside while the tight end occupies and underneath zone defender, preventing him from sinking back. That leaves Coleman completely uncovered as he breaks into the end zone, and Matt Ryan finds him for a touchdown.

While at first glance, signing McKinnon to a big contract might have appeared to be an odd decision by the 49ers, it’s clear that a running back with receiving ability is a big part of Shanahan’s offense. Look for McKinnon to run routes out of the backfield and be used as a piece to create positive matchups on less athletic linebackers.

Read more NFL coverage: