Wright, 21, made his 18th appearance of the season in Wednesday's 4-1 Scottish Cup win over Stenhousemuir.

Robson, 22, has played three games for Sunderland Under-23s this term.

O'Sullivan, 25, has played 22 times for Blackpool this term and McGowan, 29, 26 games for Bradford.

The latter, who can also play in midfield and has 20 caps for Australia, started at Hearts, had a spell with Dundee United and joined Bradford from Al-Sharjah in 2018.

Dundee say six players - Sofien Moussa and fellow striker Jean Alassane Mendy, winger Roarie Deacon and midfielder Elton Ngwatala - have left Dens Park "by mutual consent".

Meanwhile, centre-half Ryan Inniss has had his season-long loan cut short and returns to Crystal Palace as Jim McIntyre restructures his squad with Dundee sitting second bottom of the Premiership.

French-Tunisian Moussa joined the Dens Park from Bulgarian club Lokomotiv in 2017, but the 30-year-old has only made 13 appearances this season and has not scored since a double in a 4-0 League Cup victory over Stirling Albion in July.

Deacon moved to Dundee in the summer of 2017 after leaving English non-league side Sutton United and made 43 appearances for the club.

Madianga made 15 appearances since arriving from Le Mans in the summer, former Lokeren striker Jean Alassane Mendy played 11 times and Ngwatala turned out 14 times having previously been with Kidderminster Harriers.

Inniss returns to his English Premier League parent club after playing 14 times for Dundee, having been taken off before half-time in his final appearance when his short back pass helped Stephen Dobbie head for a hat-trick in Tuesday's 3-0 Scottish Cup defeat by Championship side Queen of the South.

Ryan McGowan (right) has 20 caps for Australia