Hammell's only Scotland cap was nine years ago in a 4-1 friendly defeat to Sweden at Easter Road, with the late Tommy Burns in temporary charge of team affairs.
The 31-year-old left-back is the first Motherwell player to be involved in the senior Scotland squad since Steven Saunders played against the Faroe Islands in 2010.
His club boss, Stuart McCall, is part of Gordon Strachan's coaching set-up with the national side.
Hammell told the club's official website: "People might say there have been a lot of call-offs but that doesn't matter in the slightest to me because it's a fantastic honour to represent your country.
"I was thrilled to bits when the gaffer [Stuart McCall] rang me on Wednesday. At first I thought he was winding me up then he said he was deadly serious and that Gordon wanted to know if I was available.
"I had no hesitation in telling him in the most emphatic of terms. When Gordon rang me, I was delighted to accept.
"The ironic thing is that I'm doing my coaching badges down at Largs and when the media interviewed me earlier this week, the international scene came up in the discussion."
A statement from the club added: "Everyone at Motherwell Football Club would like to congratulate Stevie on his richly-deserved call-up and wish him all the best in Zagreb."