Greg Stewart: What impact will he have on seasons of Aberdeen & Kilmarnock?
All eyes will be on Greg Stewart at Pittodrie on Saturday afternoon.
For the first half of the season he was the dynamic force at the heart of Kilmarnock's surge up the Scottish Premiership table.
After being recalled by parent club Birmingham City earlier this month, though, it will now be the red of Aberdeen he wears as second-placed Killie make the journey north to face the team only two points behind them.
Stewart has already proven himself to be statistically the most creative player in the Scottish top flight this season, but what impact will his move have on the fortunes of both teams?
Will he ignite a title challenge in Aberdeen? Will it spell the end of Kilmarnock's high-flying campaign? BBC Scotland takes a look.
Who can replace Stewart?
Stewart has provided more Premiership assists this season than any other player in a Kilmarnock kit and was the club's leading source of passes that led to a shot or immediate goalscoring opportunity.
He was also a vital outlet for goals too. With 42 shots in 16 league games, Stewart, the club's second-top goalscorer this term, had an average shots per game tally only behind Eamonn Brophy.
In Stewart's absence, manager Steve Clarke will be relying upon his two wide players - Jordan Jones and Chris Burke - to pick up the slack for the remainder of the season. Yet neither are likely to make up for the departing number 10.
Jones's own shots per game average of 1.93 is not too far off Stewart's own 2.5 per game. However, despite netting the winner against Rangers on Wednesday, the future Ibrox player does not seem to be anywhere near as clinical, with just three goals compared to Stewart's eight.
When it comes to creating goals for other players, Burke is not actually too far behind his former team-mate.
The right winger has just one fewer assist in the league than Stewart but his number of passes that lead to a goalscoring opportunity are on average half Stewart's tally of 0.54 per 90 minutes.
Can he help Aberdeen's title challenge?
Despite sitting comfortable in the league table - joint-third alongside Rangers on 42 points - Aberdeen's offensive record actually leaves a lot to be desired.
The Dons are ninth in the division for passes into the final third and only St Johnstone, St Mirren and Hamilton have made fewer passes into the box this season.
Similarly, Aberdeen are sixth in the division for total shots this season and fifth for touches in the opposing box.
Although Aberdeen can lay claim to having the third-most prolific goalscorers in the top flight this season, Sam Cosgrove stands alone as the club's only consistent source of goals.
After the in-form striker, boss Derek McInnes would then have to rely upon Lewis Ferguson - four goals in 18 - and Gary Mackay-Steven - three in 13.
Since Ryan Christie returned to Celtic and Kenny McLean moved to Norwich, Aberdeen have desperately missed a midfielder that can create goals as well as he can score them.
And if Stewart is allowed to play in his preferred number 10 role then he will surely provide that for McInnes's team.