"When Hendo turned up he was a young kid and at the start it was a bit like he was in awe of a few of the faces that were in the dressing room," Johnson told talkSPORT.
“Because he was such a hard-working kid and so eager to please, certain things weren't coming off.
“There were times in training when Hendo would make a minor mistake, maybe deliver a pass how somebody didn't want it, and there would be a handful of players that would look at him as if, not actually roll their eyes at him, but have that body language as if to say 'Oh, God, what's he done again'.
“You could see it getting to him. I remember speaking to him and saying 'You're here for a reason so just keep doing what got you here in the first place'. I just told him to relax, it will happen and to let it come out rather than forcing it.
“There were a few people looking at Hendo in the wrong sort of way – this pass I can picture didn't come off for Luis, so Luis was throwing his arms up and expecting more, so that is when Hendo snapped.
“I remember watching it and thinking 'great, it's good'. You can't let people run all over you or think that they can, and he's carried on with the same attitude in terms of how hard he works and the effort he wants to put in to improve."
Asked how Suarez received Henderson's outburst, Johnson added: "In a positive way. It was nowhere near a fight or anything like that, it was just to let him know he couldn't run over him.
“It was just a little warning, but I think Luis respected it and a few of the others that were around Luis at the time respected it and they gave him a bit of a break.
“There was no doubt about it, you could see the boy could play. Liverpool aren't silly and they didn't buy him to walk into the team on that day.
"They bought him because they knew Stevie [Gerrard] wasn't going to be around forever and they were tactically buying for a couple of years down the line."