The Pittodrie club has landed Derby County’s Kelle Roos, a 30-year-old Dutchman on a two-year deal, with Goodwin keen for a quality goalkeeper to battle Lewis for a starting spot.
Goodwin also revealed that defender Declan Gallagher has been given permission to seek out a new club, with Tranmere Rovers understood to be interested in the 31-year-old.
Lewis started for Aberdeen as they kicked off their pre-season preparations with victory over Buckie Thistle, but he is set to face stiff competition for a starting berth when the Premier Sports Cup and cinch Premiership campaign get under way next month.
“Obviously Gary Woods [Lewis’ deputy last season] has moved on,” Goodwin said. “We were light in that particular department. I don’t think we had good enough competition in that area last season.
“Joe Lewis is a fantastic goalkeeper and has been a great servant to Aberdeen. He’s got two years left on his contract but I want someone in there alongside Joe, both competing for that No 1 spot.
“Kelle brings with him a wealth of experience and he will help to enhance the goalkeeping team we have at the club.”
Gallagher wasn’t in the squad for the trip to Victoria Park, having suffered a slight knock in training on Friday.
“We’ve signed Liam Scales, Anthony Stewart and we’ve got David Bates and Gallagher there as well,” Goodwin said. “One or two of the guys may become surplus to requirements.
“We’ve had conversations with everybody. Those who are available know the situation and we’ll wait and see what happens over the coming days.
“But Deccy’s obviously at an age now where he needs to play regular football. We’re not going to stand in anybody’s way if they go and find something that gives them that opportunity. But for the time being, he’s very much our player.”
Aberdeen won 2-1 through goals from Christian Ramirez, via the penalty spot, and Matty Kennedy after Buckie had taken a surprise lead on 49 minutes.
However, injuries to Connor Barron, Jack MacKenzie and Kennedy took the shine off the victory.