Bayo becomes the Hoops' third January signing after Timothy Weah and Olivier Burke as Brendan Rodgers strengthens his offensive ranks for the second half of the season.
Now attention has reportedly turned to the other end of the pitch, with the club said to be closing in on three defensive recruits.
'Lewis just joined the club in the last six months.
Gutman, who is with Chicago Fire but most recently played college football for Indiania Hoosiers, was on trial at Rangers last month.
R&Flee: R. Kelly Accusers Believe R. Kelly May Leave Country Amid Investigations
In 2002, he was arrested after a video surfaced appearing to show him having sex with and urinating on a 14-year-old girl. The Henry County Sheriff's Office said no one by that name has been arrested since the warrant was issued a year ago .
Celtic lead Glasgow rivals Rangers only on goal difference at the top of the Scottish Premiership after losing the Old Firm derby 1-0 on December 29, but have a game in hand over Steven Gerrard's men.
He could soon be joined by compatriot Manny Perez.
However, Gutman will have a fight on his hands if he is to even break into the Celtic first team as left-back with cult hero and fan favourite Kieran Tierney all but sewn up the position as his - although the Scotland global is out with a hip injury at the minute - with neither Emilio Izaguirre or Jonny Hayes producing the goods in his absence - Gutman's deal could also call time on Izaguirre's second stint at the club after returning in the summer. He now plays for North Carolina State University.
Celtic are also considering a move for the 27-year-old Norway right back Omar Elabdellaoui from Olympiacos in Greece. Elabdellaoui, now at Olympiakos, is expected to cost around £4m.
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In this file photo taken on November 10, 2018 Flames from the Camp fire burn near a home atop a ridge near Big Bend, California. The tweet comes a day after Governor Gavin Newsom held a press conference with fire officials regarding fire prevention.
Celtic transfer news: Will Dedryck Boyata leave this month?
Unlike Andrew Gutman, another American trialist is set to stay at Ibrox, according to the Scotsman.
However, Atalanta want £10m for the player, who is also being chased by Lazio. He came in as a support player to the team but he's at the age where he needs to play in the next part of the season so he'll probably go out on loan'.
Saudi Arabia to notify women of divorce via text, Report
It was observed that in these cases, often referred to as secret divorces , women often end up missing out on alimony payments. The new measure was approved by the country's justice ministry on Sunday, Agence France-Presse reports citing local media.