McAllister, along with his tag team partner Rory McAllister, worked dark matches for WWE in 2003 and debuted on Heat in a losing effort against Tajiri and Rhyno on July 26, 2004.
In June 2006, vignettes began airing on Raw featuring The Highlanders exploring "the big city" and comparing the differences to their native Scotland in classic fish-out-of-water style.
The Highlanders made their Raw debut on July 3, 2006, with a victory over the duo of Matt Striker and Rob Conway. They followed this victory with another over the same team and were put on the fast track to a match for the Spirit Squad's World Tag Team Titles. When they were granted a match against Spirit Squad members Kenny and Mikey, The Highlanders were defeated after abundant interference by the other members. Throughout the month of August, The Highlanders continued to battle different tag teams until they won a triple threat tag team match over the team of Charlie Haas and Viscera and Lance Cade and Trevor Murdoch, which made them the number one contenders to the Spirit Squad's titles on the September 4 edition of Raw. They were unsuccessful in winning the titles at Unforgiven, again because of interference from Spirit Squad members not technically a part of the match.
The Highlanders went on to lose a Texas Tornado match at Cyber Sunday and a tag team turmoil match at New Year's Revolution for a future tag title shot. In-between the pay-per-views, The Highlanders briefly feuded with Lance Cade and Trevor Murdoch, with both teams exchanging wins on Heat before ending the feud on the December 4 episode of Raw, defeating Cade and Murdoch in a Roddy Piper tribute match.
In late 2006, they mostly competed on Raw's sister show Heat, occasionally making appearances on Raw, throughout 2007, primarily to job to other teams or singles wrestlers such as Snitsky. On the September 24, 2007 episode of Raw, The Highlanders interrupted a match between Paul London and Brian Kendrick and Lance Cade and Trevor Murdoch, due to The Highlanders getting tired of being held back from a World Tag Team Championship opportunity, thus the duo turning heel. Nothing came of this turn, however, as they lost a number one contenders match on November 12. They then feuded with London and Kendrick and Jim Duggan and Super Crazy, mainly on Heat.
The Highlanders had a Royal Rumble qualifying match, but lost to the team of Mick Foley and Hornswoggle. The Highlanders only appeared once on ECW before Rory tore his pectoral muscle and was sidelined for six months on February 2008. They lost to then-WWE Tag Team Champions John Morrison and The Miz. Robbie started wrestling on Raw again during this time, mostly on Heat and also formed a brief tag team with Charlie Haas during this time. Robbie also made an appearance on the March 17 episode of Raw as a part of the Raw roster taking on John Cena and Randy Orton. Robbie was the fourth man to be pinned, when Cena pinned him after a flying leg drop.
In their last televised match on August 11, 2008, they were defeated by Cryme Tyme. Both members of the team were released from WWE on August 15, 2008.