SEBASTIEN Haller said he was relieved to finally make his first appearance in a Borussia Dortmund shirt following two surgeries and four rounds of chemotherapy for testicular cancer which sidelined the Ivory Coast forward for six months. Haller, who scored 34 goals for Dutch champions Ajax Amsterdam last season, was diagnosed during a pre-season training camp in July - weeks after he had been signed for an initial fee of 31 million euros ($33.25 million). The 28-year-old returned to training earlier this month and finally made his unofficial debut as he came on in the second half of Tuesday's friendly…