If the San Francisco 49ers hope to return to the Super Bowl and take the next step by winning it, they should sign Mike Wallace in free agency. The fleet-footed Pittsburgh Steelers wide receiver is the dynamic deep threat the 49ers need.

With youngster Colin Kaepernick now firmly installed at quarterback, the 49ers must expand their offense to suit Kaepernick's skills. The first priority for head coach Jim Harbaugh and offensive coordinator Greg Roman, should be improving the vertical pass attack.

Adding Wallace is the best method for doing that. Despite his troubles in the Steel City, Wallace is a premier game-breaking weapon. Few receivers in football can match his ability to use straight-line speed to stretch a defense.

The 49ers have already experienced what having a true deep threat can do for their offense. Veteran Randy Moss may have not been a prolific performer in 2012. However, his mere presence expanded the 49ers big play potential and created openings for others.

Any time Moss took up a position in the slot, defenses had to respect his talent for getting deep. That meant Moss frequently took a safety away from run support and the underneath passing zones.

With Moss running vertical routes, the 49ers had the freedom to exploit intermediate areas in a variety of ways. This was particularly evident in the red zone. First, Frank Gore was afforded more rushing room against undermanned run fronts.

Wideout Michael Crabtree and tight end Vernon Davis were also given one-on-one coverage matchups on crossing patterns. Putting Wallace into the offense can create those same advantages.

As well as what he can do to help others flourish, Wallace would also be a major boon to 2012's 23rd-ranked pass offense. Wallace is more than a mere decoy. He is a legitimate 1,000-yard receiver.

The 49ers need that kind of player to ease the pressure on Crabtree. Their other options are questionable at best. The hero of Super Bowl XLVI, Mario Manningham, couldn't survive his first season in San Francisco.

He was laid low by a serious knee injury, suffered against the Seattle Seahawks in Week 16. Aside from the challenge he faces recovering from that injury, Manningham has struggled to prove himself as a primary receiver.

Worst still, 2012's first-round pick, A.J. Jenkins, appeared in only three games and didn't register a stat. The 49ers need another credible option for their wide receiver corps.

Since Kaepernick took over the 49ers' offense has had greater downfield potential. He is a strong-armed passer who can out-throw any coverage. Harbaugh and Roman must surround him with receivers who can make use of that arm strength.

Wallace is the perfect target. The 26-year-old has averaged over 13 yards per reception in each of his four pro seasons.

He is also a risk, having become embroiled in an ugly holdout for most of last summer. It seems the Steelers could be willing to part ways. NFL.com's Dan Hanzus recently reported Wallace's time may be up with the six-time Super Bowl winners.

Expect Wallace to push for a lucrative deal on the open market. The 49ers have fiscal power to accommodate his demands. According to ESPN.com's John Clayton, the Niners have $3.9 million worth of cap space.

That means they can afford to make Wallace their one marquee signing this offseason. He is worth the gamble from the 49ers. He would give them the perfect foil for Gore's power running and the ideal weapon for Kaepernick's downfield skills.

That could be enough to not only get San Francisco back to the Super Bowl. It could provide the extra element that lands the 49ers another Lombardi trophy.