The South African-born forward joined the club ahead of the 2013/2014 season and has racked up 37 league appearances since.
He missed most of last season, however, due to an ankle injury but has appeared in all of Edinburgh's GUINNESS PRO12 games this campaign, helping the club to fourth in the table.
However, Solomons admitted his player is still overcoming the after effects of that injury.
"Cornell has made a massive contribution to Edinburgh," he told the Edinburgh Evening News.
"There are not many people who would have had the ankle injury he has had and come back to play like he has.
"He is going to play in pain for a while. He trains and plays and has a bit of pain there, obviously. It is the kind of injury that will take 18 months to clear up. He is a class rugby player but he also has."
Du Preez has been an ever present during Edinburgh's last five GUINNESS PRO12 games, which included their 1872 Cup triumph over rivals Glasgow Warriors.
And while having to adapt his approach due to his injury, he was eyeing up another strong showing in his milestone game.
"It is definitely a landmark, it has come around quickly and I didn't really expect it," said the 24-year-old. "Hopefully I will put in a good performance.
"It is always a process that takes quite a while and obviously they said it would take quite a few months to get right, but there has been a lot of improvement. It is just something you have to deal with I guess and manage yourself during the week and get yourself right for the weekend.
"Especially now that I have been playing a lot of games I miss quite a lot of contact sessions during the week, but you just go away and do a bit of swimming and get some ice on the leg and it comes together."
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