Through the early stages of their campaign, the Warriors have called on rookie halves Adam Keighran and Chanel Harris-Tavita to fill the hole left by Johnson alongside Blake Green. While the pair have performed admirably when called upon, Smith said the team knew it was an area they needed to bolster as they look toward the future.
"We would like to have replaced Shaun with a really strong, experienced player. But when you lose a player in November of that quality it's very hard to find one right away.
"We definitely have some plans, that has gone right on from the period on the back end of last season.
"We're confident there could well be an addition or two in the next couple of weeks, and certainly we're in a fantastic position for next season."
Falling to a 2-5 start to the season, Smith also defended the current squad of players despite the poor record.
While they have showed some resilience and signs of promise, an inability to field the same team each week has been the major issue in the side being able to progress.
At various points of the season, the side have been without starters Issac Luke, Green and Roger Tuivasa-Sheck, who are seen as key players in the Warriors system.
"At the moment we haven't got enough continuity in our game. This time last year, we'd won six of our first seven, but we hardly made a change," Smith said.
"It's the number one thing to try get a group of guys that have played together in previous seasons. We were always going to have one who hadn't, but we just haven't been able to get Greeny in particular fit and firing and having everybody around him; Issac Luke as well.
"Sometimes you can lose players in other positions, and it doesn't affect you so much but in those positions it's definitely had an effect on our ability to control the game."
"We just need to not panic, keep fighting…it's just a matter of time before we get all our best players on the park, playing well and all together and we'll be okay. If we get that in a hurry we'll be back in winning form very soon."