According to a report from The Athletic, the young duo have been named as potential transfer targets for Palace in the coming window.
While Guehi and Gallagher have both had brilliant campaigns at their current clubs, they have had very differing fortunes in terms of club results.
Guehi was one of the crucial players for Swansea City as they continue to push for promotion back to the Premier League, even being named as man of the match for their 1-0 play-off semi-final first-leg win against Barnsley.
On the other hand, Gallagher has had to endure Premier League relegation with West Bromwich Albion, but he has still impressed this season, being one of their bright sparks along with Matheus Pereira.
The two players will now have to decide on their next destination if Chelsea are ready to loan them out again, with a move back to Stamford Bridge looking unlikely given the immense amount of depth in the current squad.
The main deciding factor is who the next manager at Crystal Palace will be, with Frank Lampard being named as the potential successor to Roy Hodgson, along with current Swansea manager Steve Cooper.
Both of these candidates could prove to be very appealing to both Guehi and Gallagher, with Lampard prioritising academy talent during his time at Chelsea, knowing the two players from his time at Stamford Bridge, while both of them also worked under Cooper at Swansea, where they have excelled.
If Swansea do get promoted to the Premier League, and if Cooper is still at the club by then, then they could make big pushes towards securing the services of Guehi or Gallagher, or possibly both, for the coming season.
Gallagher made a total of 31 appearances in all competitions for West Brom this season, getting two goals and two assists in a side that has struggled for goals all season.
Guehi has played in 43 games so far in all competitions for Swansea this season, being part of the side that finished with the third-best defensive record in the whole Championship.