Middlesbrough have agreed a deal to re-sign striker Luke Armstrong from seventh-tier outfit Blyth Spartans.

The 20-year-old, who was released from a youth contract by the Teessiders in 2014, will join the Premier League side at the end of the season.

Armstrong has scored 23 goals this season for Blyth, who have secured promotion from the Northern Premier League Premier Division, following his move last summer from Birmingham City.

The player's father, Alun, also manages Blyth, and he told Sky Sports News: "The biggest problem for me next season is finding a replacement for Luke. It's a massive blow for me, but I'm delighted for him because he always said that he wanted to get back into full-time football.

"It's exactly what he has got, but I have got an option to take him back on loan if that is required to help with his development. Other than that, I've got to find a replacement for him. He's going to be a huge miss."

Blyth are also expected to arrange a pre-season friendly with Boro this summer as part of the deal.