By Manchester correspondent Alex Stevens

Manchester United want to follow up the signing of Memphis Depay by finalising a deal for Ilkay Gundogan, Football Insider sources understand.

United are closing in on Gundogan as they bid to make a second major signing before the transfer window formally opens next month.

As reported by Football InsiderUnited have agreed a deal in principle with Borussia Dortmund for the 24-year-old midfielder to move to Old Trafford this summer for a fee of £21.5million.

Now United want Gundogan to show his commitment to the deal by tying him down to a contract.

The Premier League club announced on Thursday that Depay has agreed to join United from PSV Eindhoven subject to passing a medical.

The Holland international will cost an initial £18.6m rising to £23m with performance-related add-ons.

Dortmund announced at the end of last month that Gundogan will not extend his agreement with the Bundesliga club beyond 2016, paving the way for a summer transfer.

United made a formal move for the midfield anchorman after identifying him as the long-term successor to Michael Carrick.

The England international recently signed a 12-month contract extension and will continue to be part of Louis van Gaal’s plans next season but the manager has sanctioned a swoop for Gundogan after being convinced he has fully recovered from the back problem that sidelined him for 14 months.

United have extensively scouted the Germany international for the last three years after he was a central figure in Dortmund’s 2011-12 Bundesliga triumph.

Gundogan and Depay are set to be among a number of high profile signings by United this summer as they prepare to spend up to £200million on new players.