Rotherham United loanee Jamie McCart is praised by Leyton Orient boss Richie Wellens
The Scot joined the Millers in the summer on a three-year deal following the expiry of his contract with St Johnstone.
McCart has found opportunities hard to come by at United, with injury not helping his cause.
He has made ten appearances for the South Yorkshire club.
Ex-Doncaster Rovers boss Wellens said: "We’re delighted to welcome Jamie to the club, (he's) someone with a brilliant left-foot, dominant in the air, and ready to hit the ground running.
"Jamie comes with a winning mentality having won trophies in Scotland, and his experience is something that will be a big boost to the team.”
McCart began his career in Scotland with Celtic’s academy and enjoyed loan spells with the likes of St Mirren, Alloa and Inverness Caledonian Thistle before joining the latter on a permanent basis in 2018.
The left-sided centre-half, capped for Scotland at under-19 and under-21 level, made 62 appearances in all competitions for the Highland outfit before heading to Perth.
On the incoming front, the Millers have brought in two defenders already this month in the shape of Sean Morrison and Leeds loanee Leo Hjelde.
On heading to Orient, McCart added: "As soon as I heard about the opportunity here I was extremely interested.
"I like to defend, I like to do the basics well, but of course I like to get on the ball and play. Having spoken to the gaffer, I think I’ll fit in very well.
"I want to come on and help the team, impress as much as I can and get games, looking to get as much playing time as I can."
York City fans favourite Mitch Hancox has signed a two-year contract with the club.
Extending his stay until 2025, the 29-year-old initially joined on loan from Hereford in October 2022.
A run of 12 goals in 39 appearances during City’s road to promotion was followed by a permanent switch and he has continued to play a key role during the club’s return to the National League.