The Dane joined the Magpies in a £2million deal from Dutch side Heerenveen in 1997 as then-United manager Kenny Dalglish looked to plug the significant gap left by the sale of Les Ferdinand to Premier League rivals Tottenham Hotspur.
Tomasson showed plenty of promise in pre-season with goals against the likes of PSV Eindhoven, Birmingham City and Chelsea - but a serious injury suffered by Alan Shearer in the latter of those friendlies thrust the young Dane into an unfamilar role as United’s lead striker.
Tomasson ended his one and only season at St James Park with just four goals in 35 appearances in all competitions and returned to Holland with Feyenoord in a £2.5m deal in July 1998.
Speaking about his time on Tyneside during an interview in early-2020, Tomasson told Goal: “In England I had Kenny Dalglish as manager and he was a gentleman, no doubt.
“He kept his word to the players, and always behaved very correctly to anyone.
“In that way, I probably took some of his behaviour as a manager with me. It was not an easy season for Dalglish, for the club or for me personally.
“I arrived in Newcastle to form a partnership with Alan Shearer and then Shearer was seriously injured.
“I was young and inexperienced and I had to play out of position to fill the void after one of the best strikers in the world was injured.
“But it was still a great experience to have also played in the Premier League.”
The talented forward went on to enjoy a stellar career as he became an Eredivisie and UEFA Cup winner with Feyenoord before winning the Champions League and Serie A with Italian giants AC Milan.
Tomasson announced his retirement from playing in 2011 after spells with Stuttgart, Villarreal and a second stint with Feyenoord before moving into coaching with Dutch sides Excelsior and Roda JC.
After working on the coaching staff of the Danish national side, Tomasson was named as manager of Swedish side Malmo in January 2020 and led the club to consecutive league title wins as well as reaching the group stages of the Champions League.
Tomasson will now return to England to take charge at Blackburn after being chosen as successor to former manager Tony Mowbray.
Sky Sports have reported the 45-year-old will be officially appointed over the next 48 hours once he has been granted a work permit.