Actually, Bhagavān is Kṛṣṇa because He has got cent percent qualities of Bhagavān. That is analyzed in Caitanya-caritāmṛta. He is cent percent Bhagavān. Others, they are also Bhagavān, viṣṇu-tattva, Nārāyaṇa, He is also Bhagavān. But Śrīla Rūpa Gosvāmī has analyzed; He is 94%, not cent percent. Or, in other words, you can take it that ṣaḍ-aiśvarya pūrṇaḥ, that is Kṛṣṇa. And They are also ṣaḍ-aiśvarya, but it is not displayed. Not that... Just like Lord Rāmacandra. Lord Rāmacandra... Madhva has approved, He, also Bhagavān. Rāmādi-mūrtiṣu kalā-niyamena tiṣṭhan (Bs. 5.39). Lord Kṛṣṇa, the Supreme Personality of Godhead, is existing as the Supreme Person along with Rāma, Nṛsiṁha, Varāha, many thousands of avatāras. They are also Kṛṣṇa. Keśava dhṛta-rāma-śarīra jaya jagadīśa hare. Keśava dhṛta-mīna-śarīra jaya jagadīśa hare. So Keśava, Kṛṣṇa, He is existing with all the incarnation, not that He is existing as Kṛṣṇa. So when we speak of Kṛṣṇa, we take it that all His expansion and incarnation.
Therefore it is said rāmādi-mūrtiṣu kalā. They are kalā. Kalā means partial expansion, not full expansion. Full expansion means pūrṇa. So they are also Bhagavān. But kṛṣṇas tu bhagavān svayam means bhagavatva, the authority of Bhagavān, is fully expressed in Kṛṣṇa, not in others. Therefore in the Śrīmad-Bhāgavatam it is said... After making the list of different incarnation, it is summarized that ete cāṁśa-kalāḥ puṁsaḥ kṛṣṇas tu bhagavān svayam: (SB 1.3.28) "All these incarnations mentioned," rāmādi-mūrtiṣu kalā-niyamena tiṣṭhan (Bs. 5.39), "they are partial expansion and expansion of the expansion or expansion of His power, śaktyāveśa-avatāra."
Just (take) Lord Buddha. He is śaktyāveśa-avatāra. Many śaktyāveśa-avatāra. So in this way Kṛṣṇa is always existing along with His expansion and incarnation. But the real original Personality of Godhead is Kṛṣṇa. Kṛṣṇas tu bhagavān svayam (SB 1.3.28). Therefore Bhagavad-gītā is being spoken by Kṛṣṇa. But in order to distinguish Him, Vyāsadeva is writing śrī bhagavān uvāca. He does not say, śrī kṛṣṇa uvāca just to make it distinguished that kṛṣṇas tu bhagavān.