The 49ers need to bolster a pass rush that finished 29th in sacks last season. The pickings are looking slim on the free-agent market, but the Dolphins’ decision to give upcoming free agent defensive end Olivier Vernon the transition tag Tuesday should jolt general manager Trent Baalke into action.

The rules of the transition tag allow other teams to negotiate with tagged players and not give up additional draft picks as compensation if signed.

Although Vernon played defensive end in the Dolphins’ 4-3 scheme while the 49ers run a 3-4, he could fill a need in San Francisco as an upright pass rusher to provide much-needed depth to the defensive front. But he will be one of the most coveted players on the market, and the Dolphins will have a chance to match any offer.

The transition tag will pay Vernon $12.734 million if he sticks with Miami in 2016, and his price isn’t driven up by another club’s offer. Unlike what the Jets are doing with Muhammad Wilkerson, the key difference between transition tag and the non-exclusive franchise tag is a tagged player’s new team would not have to give up two first-round picks as compensation.

At 25, Vernon is just entering his prime after being one of the most productive edge players in the NFL last season despite his misleading sack total of 7.5. Outside linebackers Aaron Lynch and Ahmad Brooks tied for the 49ers’ team lead in 2015 with 6.5 apiece, while no other player had more than 2.5.

The Dolphins’ reluctance to give Vernon (6-2, 275) the exclusive franchise tag stems from being one of two teams projected to be over the $155.27 million salary cap. If he were given that tag and not the transition tag, he would cost $15.7 million this season and no other teams would be able to negotiate.

Vernon has started 46 of his last 48 regular season games with the Dolphins after getting drafted in the third round in 2012, notching 29 sacks. The 49ers are projected to have $55 million in cap space, which could increase by nearly $8.5 million if Colin Kaepernick is traded.