The game will be played behind closed doors at United's Benton training ground at 1pm (BST), with Clark hoping to build on a strong 45 minute showing - and a clean sheet - in the Crewe clash.
The 30-year-old suffered an ankle injury in the Magpies' Premier League defeat at Arsenal back in February, but was able to take part in the first day of pre-season training last week and is now looking to build up his match sharpness after that long lay-off.
"It feels good," Clark told nufc.co.uk when asked about his ankle. "I've had a couple of weeks in the gym doing strengthening work and trying to prepare myself as best as I can to join in with the lads in training and I've had a good rehab now. I feel pretty good and it's just good to be back involved, training with the boys.
"I'd been out for about six months and it was nice, first of all to get back training with the boys - every day now I've just been training with the boys outside - and it was great to be involved and play 45 minutes. It felt great."
The former Aston Villa man had been in excellent form for Steve Bruce's side before he was hurt in a challenge with Bukayo Saka at the Emirates Stadium.
"I just wanted to keep playing games and felt that we were on a good run of games and doing pretty well at the time, so it was just unfortunate, the timing of the injury," he said. "But it's one of those things in football and I've just had a long recovery there. The plan was just to try and come back when the boys were back in training; luckily enough I've done that and hopefully I can come through the next three weeks well."
Clark was joined by Florian Lejuene, Fabian Schär and Jamaal Lascelles on the treatment table towards the end of the last campaign, while Paul Dummett was ineligible, leaving Federico Fernández as United's only fit senior centre-back and forcing the likes of Emil Krafth and Danny Rose to play as auxiliary central defenders.
"It was a frustrating time for everyone involved," admitted Clark. "We all know that injuries are part of football but the luck we had last year with injuries wasn't very good so hopefully this year we can turn it round and a lot of the boys stay injury free."
Barnsley dramatically escaped relegation on the final day of the last Championship season, and Clark expects them to provide a good test for United following Tuesday's 3-0 win against newly-promoted League One side Crewe.
But he said: "I think games at this stage are just abut getting minutes in - we can do the 11-v-11s out in training but it's just nice to have that opposition to play against. It makes it more realistic. They'll also want to win and they're also trying to get fit for the first league game themselves.
"It's a short pre-season but it's a time for getting minutes in the tank and getting minutes on the pitch, and preparing ourselves as well as possible for that first Premier League game.
"We want to win games in pre-season but at this moment in time I think it's more important to be getting minutes in and keep as many people as possible injury-free going into that first game."
