Stliyan Petrov was no stranger to success during his seven years in Glasgow, and the ex-Aston Villa and Bulgaria international remains impressed by the current crop of Celtic talent.

Shortly after the final whistle following Celtic's thrilling 5-0 rout of Kilmarnock at Rugby Park on Wednesday evening – which saw Brendan Rodgers' side clinch their third successive league title – Petrov took to social media to congratulate his former employer.

"Hard work, passion and determination! Champions, again. Well done," read the former midfielder's message, tagging the official Celtic Twitter/X account alongside three green hearts and a trophy emoji.

Petrov himself one featured in an emphatic clean sheet, cup-winning victory over Kilmarnock when Martin O'Neill's men overcame the Rugby Park side 3-0 in the final of the Scottish League Cup in 2001.

That afternoon, a Henrik Larsson hat-trick marked the first of three trophies won by the Hoops during the 2000/2001 trail. Last night's Scottish Premiership title win, on the other hand, was decided by goals from Adam Idah, Daizen Maeda, James Forrest and a Matt O'Riley brace.

The win marks the first trophy of Brendan Rodgers' return to Celtic as manager, with his side's sights now set on their Scottish Cup Final 2024 encounter with Rangers on Saturday, May 25.

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Elsewhere, ex-Celt Jeremie Frimpong took to social media with a similar congratulatory message aimed at Glasgow's East End and his former club. The likes of Callum McGregor and James Forrest worked closely with the 23-year-old during his time at Celtic Park.

"Both champions, love it," said Frimpong on Instagram accompanied by a love-heart eyes emoji.

Now at Bayer Leverkusen, the 23-year-old has played an integral part of the Bundesliga side's current unbeaten run under Xabi Alonso – at the time of writing standing at 49 games undefeated, having already won the league and reached the UEFA Europa League final.