The right-wing-back returned from a month out injured with a high ankle sprain when Liverpool drew 2-2 at Newcastle two weeks ago, and then when Liverpool thumped West Brom 4-1 at Anfield last weekend.
The England international was, however, taken off in the second half of both games, raising concerns over his availability of this weekend’s big game in North London.
He told the club’s official website, “I’m fine for Saturday. I’ve had a sore knee for a few weeks, but it’s nothing to worry about and I just came off as a precautionary measure, really.
“It’s always a difficult period when you are injured and you are watching training and seeing the lads playing in the games, which is exactly what you want to do. It’s hard at times, but it is part of the job and you’ve just to grind them days out.”
Liverpool travel to the Emirates for Saturday (there’s live coverage of Liverpool on talkSPORT) evening’s late kick-off knowing that victory could see them leapfrog Arsene Wenger’s men into first place.
Johnson says spirits are high in the Liverpool camp right now, and hopes that continues as the season progresses.
“We’ve always had a good mood in the dressing room,” he added.
“There’s a good bunch of lads, everyone’s willing to work hard and I think that’s showing in the games. Everyone’s willing to fight for each other.”