Jose Mourinho's side seem to be edging closer to striking a deal with Madrid for Morata, although the two clubs are still yet to agree a fee for the Spain international. But Saunders thinks the Red Devils should have opted for Defoe, whose move to Bournemouth was finalised on Thursday (29 June).
"I would have taken [Jermain] Defoe me," Saunders told talkSPORT, relayed by Football 365. "He's 34, scored 15 goals last season, couple of years in him. His instinct of getting to the ball first in the box is brilliant.
"I'd have him in the squad, you're gambling, every time you sign a striker from abroad it's a gamble. I don't think it's a gamble with Defoe. He's my favourite player, Jermain Defoe is my favourite player. I love watching him.
"I like how his brain works and how he can finish, he finishes all types of chances. He doesn't drink, he's fit as a fiddle. He will (start) if he scores every week."
Defoe scored 15 goals for Sunderland last season as they miserably gave up their Premier League status. The England international was allowed to leave the Black Cats on a free transfer as a result of their relegation and Bournemouth moved quickly to bring him back to the south coast for a second spell and tie him to a three-year deal believed to be worth £130,000-a-week, according to the Mirror.
Manchester United, perhaps unsurprisingly, did not try to sign Defoe, 34, but are very much in the market for a new forward. Along with their well publicised courting of Morata, who scored 23 goals for Real Madrid last season, Manchester United have reportedly submitted a bid for Everton forward Romelu Lukaku, currently valued at £100m by the Toffees.
Torino forward Andrea Belotti is another goal ace believed to be on Manchester United's radar, with Mourinho looking to replace the indomitable Zlatan Ibrahimovic, whose spell at Old Trafford was cut short due to injury, and Wayne Rooney, who is destined to call time on his career with the Europa League winners this summer.