Arsenal have agreed a deal to sign Belgium international Leandro Trossard from Brighton for £21m plus add-ons.
League leaders Arsenal have made the move after missing out to Chelsea on signing Ukraine winger Mykhailo Mudryk.
Trossard has scored seven goals and provided three assists in 16 top-flight games for Brighton this season.
He scored a hat-trick in a 3-3 draw at Liverpool in October but was dropped by De Zerbi for the 3-0 win against the Reds on 14 January after he left training early without permission.
Trossard's agent Josy Comhair said his client, who joined Brighton from Belgian side Genk in 2019, had a calf injury but added a January transfer would be "beneficial for both parties".