Although Michail Antonio has been superb under David Moyes, another body would give them extra options, and a greater ability to cope with injuries over the course of a season.
Furthermore, Arsenal have been linked with Calvert-Lewin in the past, so they may feel the pressure to secure the arrival of a top-quality striker such as Vlahovic while they have a good chance, particularly if one of their other options is snapped up by West Ham.
And finally, a huge £60m deal for the Everton frontman may put into perspective what Vlahovic is really worth.
Calvert-Lewin has proven himself at Premier League level, but has only scored three goals so far in an injury-hit campaign.