The Reds began their pre-season with a 5-0 win at non-league Stalybridge Celtic on Wednesday and are now due to travel to Nice in France tomorrow where they will have a week-long training camp.
They are set to face French fourth division champions Toulon on Tuesday.
Kieffer Moore, Dimitri Cavare, Mike Bahre, Jacob Brown, Dani Pinillos all missed Wednesday’s game with minor injuries while Kenny Dougall is the only longer-term doubt.
Stendel said: “It will be good to train with all the players together and develop the team spirit which will be a big point for us to stay in the Championship with a young squad.
“We need to be one unit if we are going to achieve what we want.”
Barnsley are then due to return to Oakwell for a day before flying out to Germany where they will face Bundesliga 2 sides Bochum, on July 17, and Arminia Bielefeld on July 20.
Their final pre-season match is at home to Sheffield United on July 27.
Stendel said: “It will be an experience for the players.
“We will play two Bundesliga 2 teams which will be good competition for us.
“It will be a busy time but it will help us for the season.”
At Stalybridge, hundreds of Reds fans saw their side win 5-0 thanks to Cauley Woodrow’s brace and goals by Alex Mowatt, Jordan Green and Callum Styles.
Stendel said: “After one and a half weeks of training, it’s good to have a game. It’s good that the players showed they are in shape. It was a good start.
“We had lots of fans there and I knew we would. It’s a good sign.
“The players liked it. It felt like a home game. We only play two friendlies in the UK this season so they had a chance to see the team.”
Barnsley begin their season at home to Fulham, who dropped out of the Premier League last season, on August 3 then travel to bitter rivals Sheffield Wednesday a week later for their first away game. Stendel said: “We like the fixtures. We want to play in the Championship against big teams.
“It’s good motivation for everyone.
“I am looking forward to especially the first game at home.
“It is similar to last season (when Barnsley started at home against Oxford and won 4-0) and the best thing would be if we start the same, but it is not so easy.”
Stendel admits he is not an expert on the Championship but is expecting a significant step up in the quality of opponents after a season in League One.
“I have watched some games but not so many games. I think the speed is higher than League One and there is more quality across all the players.
“In League One, we had some of the best players but, in the Championship, we have players who are not the best in the league but they are still very good and they can improve.
“But they are also low on experience. The tricky task is for us to improve them.
The main thing is to improve throughout the season and have the same support from the fans as last season.
“The fans were amazing last season and it helps our team and the young players especially.”