Having been told by Blades manager Danny Wilson to seize his opportunity when selected in the first-team, Porter made an immediate impact after being introduced as a half-time substitute for Dave Kitson in his first match for the club since his return from his Shrewsbury loan. He scored the equalising goal 20 minutes after arriving on the pitch to earn a 1–1 draw with Walsall on 6 April 2013. Following Wilson's dismissal as manager, caretaker manager Chris Morgan selected Porter to start for his first game in charge on 13 April. Porter scored the opening goal of the game in a 2–0 win over Swindon Town. This goal represented a personal milestone for Porter, being his 100th career goal. He ended the season with four goals for United in 28 appearances.
