The 23-year-old defender is delighted to be back with his teammates, as the Whites start their preparations for the 2015-16 campaign.
Earlier today, Cooper posted the following message on Twitter, clearly showing that he is looking forward to getting back to business.
Cooper, who has been on the books of Leeds since last summer, will be looking to impress new head coach Uwe Rosler in the coming weeks.
The former Hull City prospect did not have exactly a great debut season at Elland Road in 2014-15, although he was made the team captain midway through the campaign.
The former Chesterfield defender scored one goal and created three chances in 29 Championship appearances last season.
Cooper had a pass accuracy of 72% and a shot accuracy of 43%, and won 91 headers, 11 dribbles and 40 tackles.