The 33-year-old Irishman injured his shoulder in the 4-3 home defeat to Aberdeen four days before Christmas.
He made his return to first-team duty with a second-half substitute run-out against William Hill Scottish Cup fifth-round opponents Stranraer last weekend.
But Foran claims he ended up delaying his comeback by pushing too hard during his recovery.
The former Motherwell midfielder - who came through an under-20s clash with Hamilton on Tuesday unscathed - told CaleyJagsTV: "It was good to get 90 minutes under my belt. It was five or six weeks since my last full game so it was a good work out for the lungs and the body.
"It was good to get through the game without any more shoulder problems as that's what we were testing.
"It is still irritating me a little bit but I'm getting through the games which is all that matters.
"I probably made the injury worse than it should have been. I tried to push myself too early. I have got to realise that I'm a bit older now and that my body can't handle as much as it used to."
Hearts boss Gary Locke faces making the long trip without five of his first-team troops.
The Tynecastle boss was this week rocked by the news winger David Smith has been ruled out for six weeks with a fractured knee, joining long-term casualties Jason Holt and Jamie Walker (both foot) on the sidelines.
And the painfully-thin Gorgie squad's task has also been hit by suspensions which count out defender Kevin McHattie and striker Callum Paterson.
On-loan West Ham striker Paul McCallum made his debut in the League Cup semi-final defeat to Inverness at Easter Road a fortnight ago, missing the Jambos' first spot-kick in the 4-2 penalty shoot-out defeat.
But basement boys Hearts have the chance to gain revenge, and McCallum said: "The semi was a chance wasted and everyone was gutted afterwards.
"But the gaffer came in and said if we had a choice between a cup final and staying in the league, he'd take the latter and getting as many points as we can had to be our focus now."
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