Lukas Engel could return to the Middlesbrough squad for Saturday's trip to Plymouth Argyle, with the left-back now back in full training. But Michael Carrick is likely to be without Luke Ayling after his injury against Millwall, while Marcus Forss and Aidan Morris remain out.

Engel has been out since August after playing through the early weeks of the season with an injury, before Neto Borges's arrival allowed Boro to finally take the Dane out of the firing line. Returning to do some training last week, he still wasn't ready to return to the squad last weekend for the Millwall win, but could be drafted back in this weekend.

It comes as fellow full-back Ayling is a major doubt for the trip to Devon after suffering an injury in that Riverside victory. Though he went off early on to have stitches in foot, it was actually a collision with Ben Doak that injured his knee which is causing the 33-year-old the biggest problem ahead of the weekend.

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Offering an update on Boro's injury picture ahead of the final game before Christmas against Plymouth Argyle, Carrick said: "We're still seeing where Luke [Ayling] is. He had a bad gash on his foot which had stitches in but it was the knee he came off with and it's the knee that's more the issue. Hopefully he won't be too long but we're still waiting to see.

"Aidan [Morris] is back on the grass, he's not training with us but day by day he is getting closer. Lukas [Engel] is back fully training with us. He's been out for quite some time but he's been back fully training for two or three days. Darragh [Lenihan] and Tommy [Smith] are further down the line."

Having missed the start of the season due to an injury suffered towards the end of last, Forss is another Boro player who has had a frustrating time with injuries of late. He returned to make two sub appearances in early October before missing the next five games. He returned for two more and was unused from the bench in the win over Hull City, but has been absent for Boro's last three with what Carrick previously described as a minor setback.

Offering an update on the Finn, Carrick said: "Marcus isn't far away from being back in and around the group. He just had a little niggle but that wasn't a big deal. It's frustrating for him. It's not for a want of trying and it's only a little niggle he's picked up, so he shouldn't be too long. That's why you need the squad. You always pick up little bits, but at the moment we're all in decent shape."