The Baggies were head of the queue to bring the defender back to The Hawthorns for a second successive season – but only on another loan deal.
Parent club Brighton, though, preferred to sell the defender, who turns 26 today, and Bruce was forced to wait to see if he went elsewhere.
Clarke chiefly operated on the left of Albion’s back three last term. He racked up 33 Championship appearances last term and was named the club’s player of the year. Bruce was keen to secure the stopper’s services again but only on another loan, due to limited finances.
“I don’t mind telling you, we were looking for Clarke,” revealed Bruce, with Albion in training during the current international break.
“We had to buy him if that was the case, and we had to wait – if nobody did buy him, then we were in pole position to sign him on loan. Middlesbrough then bought him, so Erik (Pieters) came into the equation.”
Championship rivals Boro, who took Alex Mowatt on loan from The Hawthorns, made a late move to bring Clarke in on a permanent basis, with a move in the region of £2.2million and initial three-year deal at The Riverside.
Bruce led a formation change during the summer that has seen Albion come away from the back three he inherited from Valerien Ismael and into a back four.
Former Stoke and Burnley defender Pieters, 34, had been training at the club to maintain fitness for a number of weeks and when Semi Ajayi required ankle surgery, Bruce moved for the Dutchman.