The Spain international secured a return to La Liga in the January transfer window following a difficult 18-month spell at the west London side.
Morata moved to Chelsea FC in what was then a club record £60m deal from Champions League holders Real Madrid in 2017.
The 26-year-old left Stamford Bridge having scored 24 goals in 72 games before sealing a move to Atletico Madrid.
Chelsea FC have brought in Gonzalo Higuain on loan from Juventus to improve their options up front for the remainder of the season.
The Argentina international opened his Blues account with two goals in last weekend’s 5-0 victory over Huddersfield.
Former Chelsea FC winger Nevin outlined the difference between Higuain and Morata.
“Don’t be surprised if Morata goes to Spain and scores a whole bunch of goals again,” Nevin told Irish radio station Newstalk.
“The problem with Morata was that he was playing in a team that didn’t suit him. Even if it doesn’t suit you, put yourself about a bit. He was too easily knocked off the ball.
“That’s one massive difference between himself and Higuain. Higuain will make himself a massive nuisance and a menace. He is physically strong. The other thing is that his touch is slightly better.”
Chelsea FC will take on Manchester United in the FA Cup fifth round on 18 February in search of a place in the quarter-finals.
The Blues will face defending Premier League champions Manchester City in the League Cup final at Wembley later this month.
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