Leigh Griffiths has struck 22 times for the Leith outfit this term, including the goal which earned his side a point in the opening Edinburgh derby of the season back in August.
And it is that type of form which has Tynecastle interim manager Locke concerned ahead of their weekend trip to Easter Road.
He said: "They have got the form striker in the league. I watched them last week and to Leigh's credit, he has been first class this season.
"His movement, his touch, the goals that he has scored this season has been fantastic, and it's credit to the lad because he puts up with a lot being a local lad - a lot of people have it in for him.
"We will have to be wary of him. But it's important that we also concentrate on what we do. If we play like we did the other night, then I'm confident we can go there and get a result."
The on-loan Wolves frontman's hat-trick in last weekend's 4-2 William Hill Scottish Cup win over Kilmarnock led to unsuccessful calls from Easter Road skipper James McPake that Griffiths be included in Scotland boss Gordon Strachan's squad for World Cup qualifier with Wales later this month.
And Locke backed those call-up claims, saying: "I read last week that he's been tipped for a Scotland call-up and I certainly agree with that."