The England international endured a disappointing first campaign under Portuguese coach Jose Mourinho, who replaced Louis van Gaal in May 2016.
The Dutchman had made Smalling his vice-captain in the absence of Wayne Rooney but Mourinho appeared to show little faith in the 26-year-old.
Indeed, the Manchester United boss criticised Smalling on a number of occasions over his fitness issues.
Sweden international Victor Lindelof became the first signing of the summer transfer window on Wednesday when he completed a £30.7m move to Manchester United from Benfica.
The 22-year-old’s arrival has been interpreted to signal the end of Smalling’s spell at the club amid reported interest from their Premier League rivals Arsenal.
Speaking to ESPN FC about the possibility of Smalling completed a switch to north London, former Liverpool full-back Nicol said:
“If I am an Arsenal fan, I’d be asking, are we a place for Manchester United’s cast offs?
“Let’s be honest, that’s not to be harsh on Smalling and Welbeck, it’s just a fact.
“I see this happening because Arsenal need centre-halves. They have injury problems. I think Smalling will end up at Arsenal.”
Smelling moved to Manchester United from Fulham during Sir Alex Ferguson’s spell in charge at Old Trafford.
The Red Devils won the EFL Cup and the Europa League in their first season under Mourinho’s management.
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