Jansen has been out of the game for almost three years with a series of injuries - his last game was for Bolton in April 2006.
Despite being sidelined for so long, Jansen - who began his career at Carlisle, boasts an impressive scoring record with 66 goals in 164 league appearances.
Clark added: "We are happy to help him progress as he tries to get back into football, but it's too early to say what will happen.
"We are having a look at each other and we will take things from there."
The former Manchester United target had been on trial with Blackburn but did not earn a permanent deal.
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