Motherwell have signed defensive pair Liam Grimshaw and Peter Hartley.
Hartley, 29, has joined on a season-long loan from English League One side Blackpool while Grimshaw has signed a one-year deal after his contract was cancelled by Preston North End.
Grimshaw, 22, made 16 appearances for the Steelmen during the 2015/16 season while on loan from Manchester United.
"It's by far the best time I've had in football when I was last at Motherwell," said Grimshaw.
The move comes after Ben Heneghan moved to English Championship side Sheffield United for an undisclosed fee.
Heneghan, 23, made 41 appearances for the Fir Park side, and signed a three-year deal with Chris Wilder's men.
Versatile defender Jack McMillan has also moved on loan to Livingston until mid-January.
Manager Stephen Robinson told the Motherwell website: "We tried to bring Peter in earlier in the summer so we're absolutely delighted that we've managed to bring him in on a season-long loan.
"Peter is an experienced defender who has played at a high level in England so is a coup for us. He's someone who will coach and organise our defensive line, and provides a huge threat in the opposition box at set pieces.
"I'm happy with the shape of the squad now - we've revamped things this summer and we've brought in some really promising young players and now with Peter we have got that crucial experience at the back."
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