Kensho Watanabe offers a hello and goodbye with Philadelphia Orchestra in Tchaikovsky

Up until now, the Philadelphia Orchestra has dispatched Kensho Watanabe, its tall, affable 31-year-old assistant conductor, mostly to neighborhood and family concerts, and for special events like last Tuesday’s free Chinese New Year concert.

Subscription concerts are a different animal. They are often longer, more prestigious in the minds of many, and in the course of two hours impart something of a portrait of the artist.

If first impressions are to be trusted, there is more to Watanabe than we’ve heard before. Thursday night was his first planned subscription concert appearance with the orchestra — his subscription debut was an unplanned 2017 step-in for an ailing Yannick Nézet-Séguin — and the Verizon Hall program had its challenges. Billed in the orchestra’s advertising pitch as a celebration of the breadth and depth of Tchaikovsky’s genius, it was not quite that.

The Capriccio italien, which functioned as an overture, is rousing, but it is hardly Tchaikovsky’s best.

The Variations on a Rococo Theme belonged to the soloist, cellist Edgar Moreau, and for pure beauty it contained multitudes. The 24-year-old Frenchman is a refined player. He has a particularly lovely low register — rich, great presence, yet no edge — and his soprano notes, well, if they didn’t always ring with total security, he had other kinds of solo charisma. He offered great mirth in one fleeting variation and a diaphanous serenity in another. The tone quality of the audience, if the coughing in quiet places was any indication, could use a little work.

Watanabe gave solo bows to flutist Patrick Williams and hornist Jeffrey Lang, and deservedly so.

The first movement of Tchaikovsky’s Symphony No. 1 in G Minor made you wish the entire concert had been as sure-footed and sophisticated. Part of it was the orchestra, which does Tchaikovsky like no other, and part the piece, which carries the delightfully vague subtitle “Winter Daydreams” (there are all kinds of daydreams, after all). What a trenchant, inspired first few minutes of symphonic music this work has, and Watanabe made it incisive and explosive in all the right places. The ensemble carried its saturated, signature sound, yet never wallowed.

The second movement was more moderately imagined, less opinionated, and one suspected that a few details of the third-movement scherzo’s emotional life remained to be sharpened in the conductor’s mind — except for the more relaxed middle section, which was handsomely shaped and expressive.

The last movement is the work’s least focused, and if there is a more convincing way with it, it will have to wait for another time.

This is Watanabe’s last season as assistant conductor, and he is not scheduled to return on the subscription series next season. (He will lead the annual concert for college students in the fall). Conducting is a treacherous business, though, so should a scheduled maestro fall through, Watanabe knows the drill.

Additional performances at 2 p.m. Friday and 8 p.m. Saturday in Verizon Hall, Broad and Spruce Streets. Tickets: $10-$163. philorch.org, 215-893-1999.