West Brom complete sixth summer signing - with three poised to exit

The Baggies are hunting replacements for the latter pair after selling right-back Furlong to Ipswich and agreeing a deal for winger Fellows to join Southampton, the latter for a fee which could eventually rise to £10m.

Mepham’s arrival, for a fee believed to be in the region of £1m, will see another academy product, Caleb Taylor, join Millwall on a permanent deal.

Albion received an initial £3.5m for Furlong, their longest-serving current player, with a further £500,000 due if Ipswich win promotion to the Premier League.

Fellows, meanwhile, will bring to an end his long association with the club when he completes his move to the south coast.

The 22-year-old, who first joined the academy as an under-10, has gone on to make 96 senior appearances, racking up the joint highest number of assists in the Championship last season.

Southampton, who saw a bid for Fellows turned down last summer, made their move after selling their own academy star, Tyler Dibling, to Everton for an initial £35m.

While the fee Albion will receive for Fellows has come as a disappointment to some supporters, the club believe the deal represents good business.

Mepham has become their sixth signing of the window but will not be the last, with the sales of Furlong and Fellows setting up a hectic finish.

The 27-year-old Wales international, who joined Bournemouth for £12m from Brentford six years ago, helped Sunderland win promotion during a loan spell in the Championship last season.

Mepham said: "I’m obviously aware of what a fantastic opportunity this is and at 27 I’d say I’m probably approaching the most important part of my career.

“I feel ready for a new adventure. Last season I had a really enjoyable loan spell at Sunderland, and this time around I feel like I’m ready to move on a permanent deal and find a home for the coming years.

“The conversations I’ve had with the manager and other people at the football club have been really positive. Hopefully now we can create something really special here.”

Albion sporting director, Andrew Nestor, added: “Chris brings a wealth of Premier League and Championship experience to the dressing room, including being part of a play-off winning team last season.

“At 27, he offers additional quality to a revamped defensive unit, comprising a balance of players in their prime and in development years who all offer versatility across the back line.”