Barnsley are trialing former Liverpool full-back Brad Smith with a view to signing the player as a free agent.
Australian Smith, aged 21, joined Liverpool in 2013 having been scouted while playing for his local high school.
And with young full-backs James Bree and George Smith unlikely to play every game this season, Smith could be a welcome addition to the Reds’ ranks.
Bree has recovered from injury and could start against the Robins this weekend, while winger Ryan Williams is also available having recovered from a troublesome groin injury.
“We’ve got a pretty much fully fit squad to chose from, which is great,” said Johnson, ahead of today’s home clash with Swindon Town.
“We’ve been working hard on communication this week.
“We need to improve on that because we’re a young squad.
“We had a match against Lincoln in the week which I played in myself.
“The reason behind that was to help the midfield with talking to each other.
“I had detailed conversations with all the midfield throughout the game.
“They are great players but I wanted to give them that guidance.”