The 32-year-old, who missed a large chunk of last season, featured in the first two pre-season games at Alfreton Town and Matlock Town but was not involved against Bradford City or Port Vale
On Denton, Rowe told the DT: “He has had a pretty big setback. He has had a scan and he has got to go see the specialist now so it could be not so great in terms of a couple of months out or it could be longer than that so that is where he is at.
“Obviously you feel for the lad because he has worked so hard, he has got himself into great shape, he looked good in those games (Alfreton and Matlock) and Nik Brink (physio) has done a great job with him but unfortunately that is what has happened.”
Meanwhile, Rowe said he would like to strengthen his squad further and that there will be a departure.
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“We obviously need to bring a couple in and one will be going out and then that will be us done,” he said.
“We have got to remember I only came in seven-and-a-half months ago so there has been a lot of turnover in players in what I believe, and what my staff believe, that we need to get out of this hard division.”
Fraser Kerr and Curtis Weston were both given their first starts of pre-season in Saturday’s 1-0 defeat to Port Vale and played 45 minutes.
Laurence Maguire missed out due to a migraine, while Gavin Gunning was taken off at half-time with a knock which saw Curtis Weston drop into centre-back.
“You play pre-season games to learn things and today I have learnt that Curtis can drop into the middle of a back three and be comfortable so credit to him,” Rowe said.
On the performance, he added: “I thought we had a really good first 25 minutes, dominated the game but then they had the better of the next 20 minutes.
“I am pleased with a lot of the performances and the relationships that are building. I thought Manny (Oyeleke) and (Saidou) Khan particularly in the second-half combined well.”