Motherwell boss Stuart McCall has signed defender Mark O'Brien on loan from Derby County until January.
The 21-year-old's arrival follows the signing yesterday of striker Henrik Ojamaa on loan from Legia Warsaw.
McCall told the Motherwell website: "We are delighted Mark has joined us - he is a player we have tracked for some time now.
“He would have been here much earlier but had a slight ankle knock during pre-season. Now that is clear, we are pleased to have him in the squad.
“Everyone I’ve spoken to rates him highly and this is a great opportunity for him to stake a claim for a regular first-team start."