The move for Welbeck now means the Blues are prepared to listen to offers for young forwards Emmanuel Emegha and Liam Delap.
The potential arrivals signal a significant shift in strategy, adding seasoned leadership to a crowded Stamford Bridge front line.
Emegha only recently arrived from Strasbourg and could leave on loan to secure regular developmental minutes, while Delap’s suitors are already circling, including Nottingham Forest, which is interested in a loan move.
Delap spurned Manchester United and Newcastle to sign for the Blues last year, but he only managed two goals in 41 appearances, including one league goal.
Injuries also interrupted Delap’s season, but he did not show enough to suggest he should be Chelsea’s leading man.
Joao Pedro remains first choice, and Nicolas Jackson is expected to depart, with Aston Villa discussing a move for the Senegal striker.
Alonso’s desire to add Welbeck to his ranks suggests a clear lack of faith in Delap and Emegha, who are both now likely to move elsewhere this window.