Ajax's preseason friendly against Werder Bremen was abandoned after Abdelhak Nouri required emergency ambulance treatment on the field.
Monaco have signed Netherlands defender Terence Kongolo from Feyenoord on a five-year deal.
Zhang arrives with West Brom looking to strengthen their profile in China, the homeland of the club's controlling shareholder Lai Guochuan.
Dabo, a full-back, becomes the club's third signing of the summer, with his move following a spell on loan in League One with Swindon last season.
Lozano had flown from Kazan to the Netherlands after Mexico's 2-2 Confederations Cup draw with Portugal on Sunday.
Herculez Gomez believes Hirving Lozano's move from Pachuca to PSV will elevate the winger to the next level.