The Red Devils have been linked with a surprise move to sign the Austria international in the 2018 summer transfer window.
Arnautovic scored 11 goals and made six assists in 31 appearances in the Premier League during his first season at the east London side.
The Austrian forward has previously worked under Manchester United boss Jose Mourinho at Serie A giants Inter Milan.
Arnautovic would certainly add more creativity to the Red Devils team but it remains to be seen whether the West Ham star has the necessary consistency to thrive at Old Trafford.
Sky Sports News reporter Solhekol believes Manchester United will have to pay in excess of £50m to sign Arnautovic from their Premier League rivals.
Solhekol wrote on his Twitter page: “Manchester United interested in signing West Ham forward Marko Arnautovic. Player not for sale. Would cost more than £50m”
Manchester United finished in second place in the Premier League table last season after the Red Devils finished above Tottenham Hotspur and Liverpool FC.
The 20-time English champions lost 1-0 to Chelsea FC in the FA Cup final at Wembley after Eden Hazard scored a first-half winner from the penalty spot.
The Red Devils haven’t won the Premier League title since 2013.
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